How to draw a coil such that you can see if it's right or left handed?

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











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If I draw a coil in tikz I usually do something like this:



documentclass[tikz]standalone
usetikzlibrarydecorations.pathmorphing,patterns

begindocument

begintikzpicture
draw[decoration=aspect=0.3, segment length=3.2mm, amplitude=3mm,coil,decorate,opacity=0.9] (1,0) -- (3,0);
endtikzpicture
enddocument


Which looks like this:



enter image description here



In some cases (for example in eletrodynamics) it might matter if the coil is right or left handed.



How can I modify the code above such that it looks like this:



enter image description here



If you have another, maybe better way to visualize the direction I am interested in it too.






tikz-pgf







share|improve this question

















  • 1




    The image quality of your second image is not very good. Can you clarify which aspect of it you'd like to replicate in your own image? There seem to be a change in line colour/line width as well as a small gap where the wire overlaps, but it is hard to see clearly in this pixelated image.
    – samcarter
    Sep 6 at 12:43











  • It only matters in a schematic for transformers. One typically adds a dot toward one end of the coil to indicate polarity.
    – John Kormylo
    Sep 6 at 12:52










  • @samcarter I want the line with change and the little gap.
    – Julia
    Sep 6 at 13:27














up vote
29
down vote

favorite
5












If I draw a coil in tikz I usually do something like this:



documentclass[tikz]standalone
usetikzlibrarydecorations.pathmorphing,patterns

begindocument

begintikzpicture
draw[decoration=aspect=0.3, segment length=3.2mm, amplitude=3mm,coil,decorate,opacity=0.9] (1,0) -- (3,0);
endtikzpicture
enddocument


Which looks like this:



enter image description here



In some cases (for example in eletrodynamics) it might matter if the coil is right or left handed.



How can I modify the code above such that it looks like this:



enter image description here



If you have another, maybe better way to visualize the direction I am interested in it too.






tikz-pgf







share|improve this question

















  • 1




    The image quality of your second image is not very good. Can you clarify which aspect of it you'd like to replicate in your own image? There seem to be a change in line colour/line width as well as a small gap where the wire overlaps, but it is hard to see clearly in this pixelated image.
    – samcarter
    Sep 6 at 12:43











  • It only matters in a schematic for transformers. One typically adds a dot toward one end of the coil to indicate polarity.
    – John Kormylo
    Sep 6 at 12:52










  • @samcarter I want the line with change and the little gap.
    – Julia
    Sep 6 at 13:27












up vote
29
down vote

favorite
5









up vote
29
down vote

favorite
5






5





If I draw a coil in tikz I usually do something like this:



documentclass[tikz]standalone
usetikzlibrarydecorations.pathmorphing,patterns

begindocument

begintikzpicture
draw[decoration=aspect=0.3, segment length=3.2mm, amplitude=3mm,coil,decorate,opacity=0.9] (1,0) -- (3,0);
endtikzpicture
enddocument


Which looks like this:



enter image description here



In some cases (for example in eletrodynamics) it might matter if the coil is right or left handed.



How can I modify the code above such that it looks like this:



enter image description here



If you have another, maybe better way to visualize the direction I am interested in it too.






tikz-pgf







share|improve this question













If I draw a coil in tikz I usually do something like this:



documentclass[tikz]standalone
usetikzlibrarydecorations.pathmorphing,patterns

begindocument

begintikzpicture
draw[decoration=aspect=0.3, segment length=3.2mm, amplitude=3mm,coil,decorate,opacity=0.9] (1,0) -- (3,0);
endtikzpicture
enddocument


Which looks like this:



enter image description here



In some cases (for example in eletrodynamics) it might matter if the coil is right or left handed.



How can I modify the code above such that it looks like this:



enter image description here



If you have another, maybe better way to visualize the direction I am interested in it too.






tikz-pgf




tikz-pgf






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Sep 6 at 11:58









Julia

684513




684513







  • 1




    The image quality of your second image is not very good. Can you clarify which aspect of it you'd like to replicate in your own image? There seem to be a change in line colour/line width as well as a small gap where the wire overlaps, but it is hard to see clearly in this pixelated image.
    – samcarter
    Sep 6 at 12:43











  • It only matters in a schematic for transformers. One typically adds a dot toward one end of the coil to indicate polarity.
    – John Kormylo
    Sep 6 at 12:52










  • @samcarter I want the line with change and the little gap.
    – Julia
    Sep 6 at 13:27












  • 1




    The image quality of your second image is not very good. Can you clarify which aspect of it you'd like to replicate in your own image? There seem to be a change in line colour/line width as well as a small gap where the wire overlaps, but it is hard to see clearly in this pixelated image.
    – samcarter
    Sep 6 at 12:43











  • It only matters in a schematic for transformers. One typically adds a dot toward one end of the coil to indicate polarity.
    – John Kormylo
    Sep 6 at 12:52










  • @samcarter I want the line with change and the little gap.
    – Julia
    Sep 6 at 13:27







1




1




The image quality of your second image is not very good. Can you clarify which aspect of it you'd like to replicate in your own image? There seem to be a change in line colour/line width as well as a small gap where the wire overlaps, but it is hard to see clearly in this pixelated image.
– samcarter
Sep 6 at 12:43





The image quality of your second image is not very good. Can you clarify which aspect of it you'd like to replicate in your own image? There seem to be a change in line colour/line width as well as a small gap where the wire overlaps, but it is hard to see clearly in this pixelated image.
– samcarter
Sep 6 at 12:43













It only matters in a schematic for transformers. One typically adds a dot toward one end of the coil to indicate polarity.
– John Kormylo
Sep 6 at 12:52




It only matters in a schematic for transformers. One typically adds a dot toward one end of the coil to indicate polarity.
– John Kormylo
Sep 6 at 12:52












@samcarter I want the line with change and the little gap.
– Julia
Sep 6 at 13:27




@samcarter I want the line with change and the little gap.
– Julia
Sep 6 at 13:27










2 Answers
2






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up vote
45
down vote













The starting point of all this is the code in pgflibrarydecorations.pathmorphing.code.tex. I acknowledge a comment by joojaa that pointed out that the halo was not quite right in the original answers. I also appreciate a comment by Robert Harvey, who encouraged me to clean up. What I did is to modify the coil decoration of the decorations.pathmorphing library. There is still a lot of room for improvement. The keys in the beginning allow you to adjust the color, opacity, width of coil and additional width of the halo, I hope the names I gave to these parameters are self-explanatory.



enter image description here



documentclass[tikz,border=3.14mm]standalone
usetikzlibrarydecorations.pathmorphing
pgfkeys%
/pgf/decoration/.cd,
3d coil color/.store in=TDCoilColor, 
3d coil color/.initial=black,
3d coil color=black,
3d coil width/.store in=TDCoilWidth, 
3d coil width/.initial=0.4pt,
3d coil width=0.4pt,
3d coil dist/.store in=TDCoilDist, 
3d coil dist/.initial=0.6pt,
3d coil dist=0.6pt,
3d coil opacity/.store in=TDCoilOpacity, 
3d coil opacity/.initial=1,
3d coil opacity=1


makeatletter % https://tex.stackexchange.com/a/219088/121799
tikzsetget stroke color/.code=%
 expandafterglobal% Jump over, now we have global
 expandafterlet% Jump over now we have globallet
 expandafterpgfsavedstrokecolor% Jump we have globalletpgf...
 csnamestringcolor@pgfstrokecolorendcsname% Finally expand this and put it at the end 
 , % globalletpgf... in expanded form 
 restore stroke color/.code=pgf@setstrokecolor#1,

defpgfpoint@onthreedcoil#1#2#3%
 pgf@x=#1pgfdecorationsegmentamplitude%
 pgf@x=pgfdecorationsegmentaspectpgf@x%
 pgf@y=#2pgfdecorationsegmentamplitude%
 pgf@xa=0.083333333333pgfdecorationsegmentlength%
 advancepgf@x by#3pgf@xa%
 advancepgf@x by-initialoffset pt%


% coil decoration
%
% Parameters: pgfdecorationsegmentamplitude, pgfdecorationsegmentlength,

pgfdeclaredecoration3d coilinitial
 
 stateinitial[width=0.25*pgfdecorationsegmentlength+pgfdecorationsegmentaspect*pgfdecorationsegmentamplitude,
 next state=coil, persistent precomputation=
 tikzsetget stroke color
 pgfmathsetmacroinitialoffset0.25*pgfdecorationsegmentlength+pgfdecorationsegmentaspect*pgfdecorationsegmentamplitude
 ]
 %
 pgfpathmovetopgfpointorigin 
 pgfsetstrokecolorTDCoilColor
 pgfsetstrokeopacityTDCoilOpacity
 pgfsetlinewidth1.5*TDCoilWidth 
 pgfpathcurveto
 pgfpoint@oncoil0 0.5551
 pgfpoint@oncoil0.445 1 2
 pgfpoint@oncoil1 1 3
 pgfusepathstroke
 pgfcoordinateTD@coilastpgfpoint@oncoil1 1 3 
 
 statecoil[switch if less than=%
 1.25pgfdecorationsegmentlength+%
 pgfdecorationsegmentaspectpgfdecorationsegmentamplitude+%
 pgfdecorationsegmentaspectpgfdecorationsegmentamplitude to last,
 width=+pgfdecorationsegmentlength]
 % line in the back
 %
 pgfsetstrokecolorTDCoilColor
 pgfsetfillcolorTDCoilColor
 pgfsetstrokeopacityTDCoilOpacity
 pgfpathmovetopgfpointanchorTD@coilastcenter
 pgfsetlinewidthTDCoilWidth 
 pgfpathcurveto
 pgfpoint@onthreedcoil1.555 1 4
 pgfpoint@onthreedcoil2 0.5555
 pgfpoint@onthreedcoil2 0 6
 pgfpathcurveto
 pgfpoint@onthreedcoil2 -0.5557
 pgfpoint@onthreedcoil1.555-1 8
 pgfpoint@onthreedcoil1 -1 9
 pgfusepathstroke 
 %
 % white background for front thick part
 %
 pgfsetstrokeopacity1
 pgfsetstrokecolorwhite
 pgfsetfillcolorwhite
 pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
 pgfpathmovetopgfpoint@onthreedcoil1 1 3
 pgfpathmovetopgfpoint@onthreedcoil1 -1 9
 % draw forward
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil0 -0.55511.25
 pgfpoint@onthreedcoil0 0 12.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 0.55513.25
 pgfpoint@onthreedcoil0.445 1 14.25
 pgfpoint@onthreedcoil1 1 15
 % draw the curve back
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445 1 14
 pgfpoint@onthreedcoil0 0.55512.75
 pgfpoint@onthreedcoil0 0 11.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 -0.55510.75
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil1 -1 9
 pgfusepathstroke,fill 
 % 
 % draw the thick foreground path
 %
 pgfsetstrokecolorTDCoilColor
 pgfsetfillcolorTDCoilColor
 pgfsetstrokeopacityTDCoilOpacity
 pgfpathmovetopgfpoint@onthreedcoil1 1 3
 pgfsetlinewidthTDCoilWidth 
 % forward shifted +
 pgfpathmovetopgfpoint@onthreedcoil1 -1 9
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil0 -0.55511.25
 pgfpoint@onthreedcoil0 0 12.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 0.55513.25
 pgfpoint@onthreedcoil0.445 1 14.25
 pgfpoint@onthreedcoil1 1 15
 % draw the curve back shfted -
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445 1 14
 pgfpoint@onthreedcoil0 0.55512.75
 pgfpoint@onthreedcoil0 0 11.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 -0.55510.75
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil1 -1 9
 pgfusepathstroke,fill % <- added
 pgfcoordinateTD@coilastpgfpoint@onthreedcoil1 1 15 
 
 statelast[width=.25pgfdecorationsegmentlength+%
 pgfdecorationsegmentaspectpgfdecorationsegmentamplitude+%
 pgfdecorationsegmentaspectpgfdecorationsegmentamplitude,next state=final]
 
 pgfsetstrokecolorTDCoilColor
 pgfsetstrokeopacityTDCoilOpacity
 pgfsetlinewidthTDCoilWidth
 pgfpathmovetopgfpointanchorTD@coilastcenter
 pgfpathcurveto
 pgfpoint@onthreedcoil1.555 1 4
 pgfpoint@onthreedcoil2 0.5555
 pgfpoint@onthreedcoil2 0 6
 
 statefinal
 
 pgfpathlinetopgfpointdecoratedpathlast
 pgfusepathstroke
 tikzsetrestore stroke color/.expand once=pgfsavedstrokecolor
 

makeatother

begindocument
begintikzpicture
draw[decoration=3d coil color=blue,aspect=0.35, segment length=3.1mm, amplitude=3mm,3d coil,
decorate] (0,0) -- (0,3);
draw[decoration=3d coil color=red,3d coil opacity=0.9,aspect=0.45, segment length=3.1mm, amplitude=3mm,3d coil,
decorate] (2,3) -- (2,0);
draw[decoration=3d coil color=green!60!black,3d coil opacity=0.9,aspect=0.35, segment length=3.1mm, amplitude=3mm,3d coil,
decorate] (4,3) to[out=0,in=90] (6,0);
endtikzpicture
enddocument


FUN: The mandatory animation can be made with the same preamble + usepackagetikzmarmots and 



begindocument
foreach X [evaluate=X as Y using sin(X)]in 0,10,...,350

begintikzpicture
path[use as bounding box] (-1,-0.2) rectangle (1,4);
draw[decoration=3d coil color=blue,aspect=0.35, segment
length=(1.2+0.7*Y)*1mm, amplitude=3mm,3d coil,
decorate] (0,0) -- (0,2);
beginscope[shift=(-0.9,1+0.5*Y)]
marmot[teeth,whiskers]
endscope
endtikzpicture
enddocument


enter image description here



BONUS: A "complete" version, i.e. an analog of Jake's complete sines with a "closed" option (analogous to the closed zigzags.)



documentclass[tikz,border=3.14mm]standalone
usetikzlibrarydecorations.pathmorphing
makeatletter
newififcoil@closed
pgfkeys%
/pgf/decoration/.cd,
3d coil color/.store in=TDCoilColor, 
3d coil color/.initial=black,
3d coil color=black,
3d coil width/.store in=TDCoilWidth, 
3d coil width/.initial=0.4pt,
3d coil width=0.4pt,
3d coil dist/.store in=TDCoilDist, 
3d coil dist/.initial=0.6pt,
3d coil dist=0.6pt,
3d coil opacity/.store in=TDCoilOpacity, 
3d coil opacity/.initial=1,
3d coil opacity=1,
3d coil closed/.code=coil@closedtrue


 % https://tex.stackexchange.com/a/219088/121799
tikzsetget stroke color/.code=%
 expandafterglobal% Jump over, now we have global
 expandafterlet% Jump over now we have globallet
 expandafterpgfsavedstrokecolor% Jump we have globalletpgf...
 csnamestringcolor@pgfstrokecolorendcsname% Finally expand this and put it at the end 
 , % globalletpgf... in expanded form 
 restore stroke color/.code=pgf@setstrokecolor#1,

defpgfpoint@onthreedcoil#1#2#3%
 pgf@x=#1pgfdecorationsegmentamplitude%
 pgf@x=pgfdecorationsegmentaspectpgf@x%
 pgf@y=#2pgfdecorationsegmentamplitude%
 pgf@xa=0.083333333333pgfdecorationsegmentlength%
 advancepgf@x by#3pgf@xa%
 advancepgf@x by-generaloffset pt%


% coil decoration
%
% Parameters: pgfdecorationsegmentamplitude, pgfdecorationsegmentlength,

pgfdeclaredecoration3d complete coilinitial
 
 stateinitial[width=0.5*pgfdecorationsegmentlength,
 next state=coil, persistent precomputation=% from https://tex.stackexchange.com/a/25689/121799
 pgfmathsetmacromatchinglengthpgfdecoratedinputsegmentlength / int(pgfdecoratedinputsegmentlength/pgfdecorationsegmentlength)
 setlengthpgfdecorationsegmentlengthmatchinglength pt
 tikzsetget stroke color
 pgfmathsetmacrogeneraloffsetpgfdecorationsegmentlength
 pgfmathsetmacroinitialoffset1.5*pgfdecorationsegmentlength
 pgfmathsetmacroauxoffset2.5*pgfdecorationsegmentlength
 ] 
 % line in the back
 %
 pgfsetstrokecolorTDCoilColor
 pgfsetfillcolorTDCoilColor
 pgfsetstrokeopacityTDCoilOpacity
 pgfsetlinewidthTDCoilWidth 
 ifcoil@closed
 begingroup
 defgeneraloffsetauxoffset
 pgfpathmovetopgfpoint@onthreedcoil1 1 15
 pgfpathcurveto
 pgfpoint@onthreedcoil1.555 1 16
 pgfpoint@onthreedcoil2 0.55517
 pgfpoint@onthreedcoil2 0 18
 pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18
 pgfcoordinateTD@coilfirstpgfpoint@onthreedcoil1 1 15
 pgfusepathstroke 
 pgfsetstrokecolorTDCoilColor
 endgroup
 fi
 begingroup %
 defgeneraloffsetinitialoffset
 ifcoil@closed
 pgfpathmovetopgfpointanchorTD@coilastcenter
 else
 pgfpathmovetopgfpointorigin
 fi
 pgfpathcurveto
 pgfpoint@onthreedcoil2 -0.5557
 pgfpoint@onthreedcoil1.555-1 8
 pgfpoint@onthreedcoil1 -1 9
 pgfusepathstroke 
 %
 % white background for front thick part
 %
 pgfsetstrokeopacity1
 pgfsetstrokecolorwhite
 pgfsetfillcolorwhite
 pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
 pgfpathmovetopgfpoint@onthreedcoil1 -1 9
 % draw forward
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil0 -0.55511.25
 pgfpoint@onthreedcoil0 0 12.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 0.55513.25
 pgfpoint@onthreedcoil0.445 1 14.25
 pgfpoint@onthreedcoil1 1 15
 % draw the curve back
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445 1 14
 pgfpoint@onthreedcoil0 0.55512.75
 pgfpoint@onthreedcoil0 0 11.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 -0.55510.75
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil1 -1 9
 pgfusepathstroke,fill 
 % 
 % draw the thick foreground path
 %
 pgfsetstrokecolorTDCoilColor
 pgfsetfillcolorTDCoilColor
 pgfsetstrokeopacityTDCoilOpacity
 pgfpathmovetopgfpoint@onthreedcoil1 1 3
 pgfsetlinewidthTDCoilWidth 
 % forward shifted +
 pgfpathmovetopgfpoint@onthreedcoil1 -1 9
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil0 -0.55511.25
 pgfpoint@onthreedcoil0 0 12.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 0.55513.25
 pgfpoint@onthreedcoil0.445 1 14.25
 pgfpoint@onthreedcoil1 1 15
 % draw the curve back shfted -
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445 1 14
 pgfpoint@onthreedcoil0 0.55512.75
 pgfpoint@onthreedcoil0 0 11.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 -0.55510.75
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil1 -1 9
 pgfusepathstroke,fill 
 pgfpathmovetopgfpoint@onthreedcoil1 1 15
 pgfpathcurveto
 pgfpoint@onthreedcoil1.555 1 16
 pgfpoint@onthreedcoil2 0.55517
 pgfpoint@onthreedcoil2 0 18
 pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18 
 pgfusepathstroke 
 endgroup
 
 statecoil[switch if less than=%
 1.9*pgfdecorationsegmentlength to last,
 width=+pgfdecorationsegmentlength]
 % line in the back
 %
 pgfsetstrokecolorTDCoilColor
 pgfsetfillcolorTDCoilColor
 pgfsetstrokeopacityTDCoilOpacity
 pgfpathmovetopgfpointanchorTD@coilastcenter
 pgfsetlinewidthTDCoilWidth 
 pgfpathcurveto
 pgfpoint@onthreedcoil2 -0.5557
 pgfpoint@onthreedcoil1.555-1 8
 pgfpoint@onthreedcoil1 -1 9
 pgfusepathstroke 
 %
 % white background for front thick part
 %
 pgfsetstrokeopacity1
 pgfsetstrokecolorwhite
 pgfsetfillcolorwhite
 pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
 pgfpathmovetopgfpoint@onthreedcoil1 1 3
 pgfpathmovetopgfpoint@onthreedcoil1 -1 9
 % draw forward
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil0 -0.55511.25
 pgfpoint@onthreedcoil0 0 12.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 0.55513.25
 pgfpoint@onthreedcoil0.445 1 14.25
 pgfpoint@onthreedcoil1 1 15
 % draw the curve back
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445 1 14
 pgfpoint@onthreedcoil0 0.55512.75
 pgfpoint@onthreedcoil0 0 11.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 -0.55510.75
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil1 -1 9
 pgfusepathstroke,fill 
 % 
 % draw the thick foreground path
 %
 pgfsetstrokecolorTDCoilColor
 pgfsetfillcolorTDCoilColor
 pgfsetstrokeopacityTDCoilOpacity
 pgfpathmovetopgfpoint@onthreedcoil1 1 3
 pgfsetlinewidthTDCoilWidth 
 % forward shifted +
 pgfpathmovetopgfpoint@onthreedcoil1 -1 9
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil0 -0.55511.25
 pgfpoint@onthreedcoil0 0 12.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 0.55513.25
 pgfpoint@onthreedcoil0.445 1 14.25
 pgfpoint@onthreedcoil1 1 15
 % draw the curve back shfted -
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445 1 14
 pgfpoint@onthreedcoil0 0.55512.75
 pgfpoint@onthreedcoil0 0 11.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 -0.55510.75
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil1 -1 9
 pgfusepathstroke,fill 
 pgfpathmovetopgfpoint@onthreedcoil1 1 15
 pgfpathcurveto
 pgfpoint@onthreedcoil1.555 1 16
 pgfpoint@onthreedcoil2 0.55517
 pgfpoint@onthreedcoil2 0 18
 pgfusepathstroke 
 pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18 
 
 statelast[next state=final]
 % line in the back
 %
 pgfsetstrokecolorTDCoilColor
 pgfsetfillcolorTDCoilColor
 pgfsetstrokeopacityTDCoilOpacity
 pgfpathmovetopgfpointanchorTD@coilastcenter
 pgfsetlinewidthTDCoilWidth 
 pgfpathcurveto
 pgfpoint@onthreedcoil2 -0.5557
 pgfpoint@onthreedcoil1.555-1 8
 pgfpoint@onthreedcoil1 -1 9
 pgfusepathstroke 
 % 
 % draw the thick foreground path
 %
 ifcoil@closed %pgfpointanchorTD@coilfirstcenter
 %
 % white background for front thick part
 %
 pgfsetstrokeopacity1
 pgfsetstrokecolorwhite
 pgfsetfillcolorwhite
 pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
 pgfpathmovetopgfpoint@onthreedcoil1 1 3
 pgfpathmovetopgfpoint@onthreedcoil1 -1 9
 % draw forward
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil0 -0.55511.25
 pgfpoint@onthreedcoil0 0 12.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 0.55513.25
 pgfpoint@onthreedcoil0.445 1 14.25
 pgfpointanchorTD@coilfirstcenter
 % draw the curve back
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445 1 14
 pgfpoint@onthreedcoil0 0.55512.75
 pgfpoint@onthreedcoil0 0 11.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 -0.55510.75
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil1 -1 9
 pgfusepathstroke,fill 
 pgfsetstrokecolorTDCoilColor
 pgfsetfillcolorTDCoilColor
 pgfsetstrokeopacityTDCoilOpacity
 pgfpathmovetopgfpoint@onthreedcoil1 1 3
 pgfsetlinewidthTDCoilWidth 
 % forward shifted +
 pgfpathmovetopgfpoint@onthreedcoil1 -1 9
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil0 -0.55511.25
 pgfpoint@onthreedcoil0 0 12.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 0.55513.25
 pgfpoint@onthreedcoil0.445 1 14.25
 pgfpointanchorTD@coilfirstcenter
 % draw the curve back shifted 
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445 1 14
 pgfpoint@onthreedcoil0 0.55512.75
 pgfpoint@onthreedcoil0 0 11.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 -0.55510.75
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil1 -1 9
 pgfusepathstroke,fill 
 else
 %
 % white background for front thick part
 %
 pgfsetstrokeopacity1
 pgfsetstrokecolorwhite
 pgfsetfillcolorwhite
 pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
 pgfpathmovetopgfpoint@onthreedcoil1 1 3
 pgfpathmovetopgfpoint@onthreedcoil1 -1 9
 % draw forward
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil0 -0.55511.25
 pgfpoint@onthreedcoil0 0 12.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 0.55513.25
 pgfpoint@onthreedcoil0.445 1 14.25
 pgfpoint@onthreedcoil1 1 15
 % draw the curve back
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445 1 14
 pgfpoint@onthreedcoil0 0.55512.75
 pgfpoint@onthreedcoil0 0 11.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 -0.55510.75
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil1 -1 9
 pgfusepathstroke,fill 
 pgfsetstrokecolorTDCoilColor
 pgfsetfillcolorTDCoilColor
 pgfsetstrokeopacityTDCoilOpacity
 pgfpathmovetopgfpoint@onthreedcoil1 1 3
 pgfsetlinewidthTDCoilWidth 
 % forward shifted +
 pgfpathmovetopgfpoint@onthreedcoil1 -1 9
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil0 -0.55511.25
 pgfpoint@onthreedcoil0 0 12.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 0.55513.25
 pgfpoint@onthreedcoil0.445 1 14.25
 pgfpoint@onthreedcoil1 1 15
 % draw the curve back shifted 
 pgfpathcurveto
 pgfpoint@onthreedcoil0.445 1 14
 pgfpoint@onthreedcoil0 0.55512.75
 pgfpoint@onthreedcoil0 0 11.5
 pgfpathcurveto
 pgfpoint@onthreedcoil0 -0.55510.75
 pgfpoint@onthreedcoil0.445-1 10
 pgfpoint@onthreedcoil1 -1 9
 pgfusepathstroke,fill 
 fi
 pgfpathmovetopgfpoint@onthreedcoil1 1 15
 ifcoil@closed %TD@coilfirst
 else
 pgfpathcurveto
 pgfpoint@onthreedcoil1.555 1 16
 pgfpoint@onthreedcoil2 0.55517
 pgfpoint@onthreedcoil2 0 18
 fi
 pgfusepathstroke 
 %pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18 
 
 statefinal
 
 pgfpathmovetopgfpointdecoratedpathlast
 tikzsetrestore stroke color/.expand once=pgfsavedstrokecolor
 

makeatother

begindocument
begintikzpicture
draw[decoration=3d coil color=red,aspect=0.35, segment length=3.1mm, 
amplitude=3mm,3d complete coil,
decorate] (0,1) -- (0,6);
draw[decoration=3d coil color=blue,3d coil opacity=0.9,aspect=0.5, 
segment length=2*pi*3cm/50, amplitude=5mm,3d complete coil,
3d coil closed,
decorate] (5,3.5) circle (3);
draw[decoration=3d coil color=green!60!black,aspect=0.5, segment length=3.1mm, 
amplitude=4mm,3d complete coil,
decorate] (0,-1) -- (0,-6);
draw[decoration=3d coil color=purple,3d coil opacity=0.9,aspect=0.5, 
segment length=2*pi*3cm/50, amplitude=3mm,3d complete coil,
3d coil closed,
decorate] (5,-3.5) circle (3);
endtikzpicture
enddocument


enter image description here






share|improve this answer


















  • 3




    The decorations in pgf, it's the most difficult, wonderful work, bravo!
    – AndréC
    Sep 6 at 16:05










  • @AndréC Merci, but I am actually not really happy, What I would love to achieve is that it is not necessary to set the color, opacity and so on explicitly. And then there are more downsides. Assume I was able to achieve this, then the decomposition of the path in little segments has further downsides such as the fact that a dashed line will not look nice. So there is a lot of room for improvement...
    – marmot
    Sep 6 at 16:09










  • You can draw two lines that overlap when they are thin but then move away from each other on the thicker part so no step function in thickness LIkewise you can draw a white line on that is thicker on the top part so overlap is along path
    – joojaa
    Sep 6 at 16:30











  • @marmot its slightly less work. The strokes overlap anyway. So no particular reason to fill stuff except pedantry
    – joojaa
    Sep 6 at 16:40






  • 1




    Another beautiful piece of marmot magic!
    – Max
    Sep 7 at 18:04

















up vote
23
down vote













If you put negative values for aspect and amplitude, you can get the mirrored coil, add this in the @marmot's answer may complete the desired output; also I added an option using markings to get some similar drawing that uses scope and yscale to invert the marking, then a new variable to control the coil color,when the path is straight it has good result, markings path lacks bending good results.



EDIT: Added a control for marking step to improve bending results.



RESULT:



enter image description here



MWE:



documentclass[tikz,border=20pt]standalone
usetikzlibrarydecorations.pathmorphing,decorations.markings

begindocument

begintikzpicture[
 CoilColor/.store in=coilcolor,CoilColor=black,
 Step/.store in=Step,Step=0.1,
 Coil/.style=
 double=black,
 draw=gray!50,
 decoration=
 #1,
 segment length=3mm,
 coil
 ,
 decorate,
 ,
 Coil2/.style=
 decorate,
 decoration=
 markings,
 mark= between positions 0 and 1 step Step
 with 
 beginscope[yscale=#1]
 draw[xshift=9.2,fill,coilcolor!70!black]
 (0,0)++(-135: 0.2 and 0.4) 
 .. controls +(-0.2,0) and +(-0.3,0) .. (90: 0.2 and 0.4)
 .. controls +(-0.33,0) and +(-0.23,0) .. (-135: 0.2 and 0.4); 
 draw[white,line width=2pt]
 (0,0)++(90: 0.2 and 0.4) 
 .. controls +(0.3,0) and +(0.2,0) .. (-45: 0.2 and 0.4);
 draw[fill=coilcolor,coilcolor]
 (0,0)++(90: 0.2 and 0.4) 
 .. controls +(0.3,0) and +(0.2,0) .. (-45: 0.2 and 0.4)
 .. controls +(0.25,0) and +(0.35,0) .. (90: 0.2 and 0.4);
 endscope 
 
 
 
]
draw[Coil=aspect=-0.3,amplitude=-3mm,blue] (0,0) -- ++ (0,-3);
draw[Coil=aspect=0.3,amplitude=3mm,red] (1.5,0) -- ++ (0,-3);
draw[Coil=aspect=0.3,amplitude=3mm,green!50!black] (3,0) arc (90:0:3);
draw[Coil=aspect=-0.3,amplitude=-3mm] (3,1) arc (90:0:4);

draw[Coil2=-1,CoilColor=blue] (0,-4) -- ++ (0,-3);
draw[Coil2=1,CoilColor=red] (1.5,-4) -- ++ (0,-3);
draw[Coil2=-1,CoilColor=green!50!black,Step=0.065] (3,-4) arc (90:0:3);
draw[Coil2=1,Step=0.048] (3,-3) arc (90:0:4);

endtikzpicture
enddocument


UPDATE:
Acording to @marmot's suggestion closing the gaps and drawing all the variations, using pgfdecoratedpathlength, /pgf/decoration/mark info/sequence number.



RESULT:
enter image description here



MWE:



documentclass[tikz,border=20pt]standalone
usetikzlibrarydecorations.markings

begindocument

begintikzpicture[
 CoilColor/.store in=coilcolor,CoilColor=black,
 Step/.store in=Step,Step=0.1,
 Width/.store in=Width,Width=0.4,
 Coil2/.style=
 decorate,
 decoration=
 markings,
 mark= between positions 0 and 1 step Step 
 with 
 beginscope[yscale=#1]
 pgfmathparseint(pgfdecoratedpathlength/28.45*100*Step)
 edefHightpgfmathresult
 ifnumpgfkeysvalueof/pgf/decoration/mark info/sequence number=1
 path (0,0)++(90: Hight/200 and Width) coordinate (b);
 fi
 ifnumpgfkeysvalueof/pgf/decoration/mark info/sequence number>1
 coordinate (b) at (d);
 fi
 path (b) arc (90:-135: Hight/200 and Width) coordinate (a);
 path (b) arc (90:-45: Hight/200 and Width) coordinate (c);
 path (b)++(Hight/100,0) coordinate (d);
 draw[fill,coilcolor!70!black]
 (c)
 .. controls +(-0.175,0) and +(-0.275,0) .. (d)
 .. controls +(-0.325,0) and +(-0.225,0) .. (c);
 draw[white,line width=2pt]
 (b)
 .. controls +(0.3,0) and +(0.2,0) .. (c);
 draw[fill,coilcolor]
 (b)
 .. controls +(0.275,0) and +(0.175,0) .. (c)
 .. controls +(0.225,0) and +(0.325,0) .. (b);
 endscope
 
 
 
]

draw[Coil2=-1,CoilColor=red,Step=0.15] (0.5,0) -- ++ (0,-3);
draw[Coil2=1.5,CoilColor=magenta] (1.5,0) -- ++ (0,-3);

draw[Coil2=1,CoilColor=green!70!black,Step=0.02] (0,-4) 
 to [in=90,out=0] ++(2.5,-1)
 to [in=180,out=-90] ++(2.5,-1)
 to [in=-90,out=0] ++(2,1.5)
 to [in=-90,out=90] ++(0.5,3) arc (0:90:2);

draw[Coil2=-1,CoilColor=green!50!cyan,Step=0.02] (0,-5) 
 to [in=90,out=0] ++(1.5,-1)
 to [in=180,out=-90] ++(4,-1)
 to [in=-90,out=0] ++(3,2.5)
 to [in=-90,out=90] ++(0.5,4.5) arc (0:90:2);

draw[Coil2=1,CoilColor=cyan!30!blue,Step=0.05] (5.7,-2) arc (360:0:1.5);
draw[Coil2=-1,CoilColor=cyan!70!blue,Step=0.05] (6.5,-2) arc (360:0:1.5);

endtikzpicture
enddocument





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    The starting point of all this is the code in pgflibrarydecorations.pathmorphing.code.tex. I acknowledge a comment by joojaa that pointed out that the halo was not quite right in the original answers. I also appreciate a comment by Robert Harvey, who encouraged me to clean up. What I did is to modify the coil decoration of the decorations.pathmorphing library. There is still a lot of room for improvement. The keys in the beginning allow you to adjust the color, opacity, width of coil and additional width of the halo, I hope the names I gave to these parameters are self-explanatory.



    enter image description here



    documentclass[tikz,border=3.14mm]standalone
    usetikzlibrarydecorations.pathmorphing
    pgfkeys%
    /pgf/decoration/.cd,
    3d coil color/.store in=TDCoilColor, 
    3d coil color/.initial=black,
    3d coil color=black,
    3d coil width/.store in=TDCoilWidth, 
    3d coil width/.initial=0.4pt,
    3d coil width=0.4pt,
    3d coil dist/.store in=TDCoilDist, 
    3d coil dist/.initial=0.6pt,
    3d coil dist=0.6pt,
    3d coil opacity/.store in=TDCoilOpacity, 
    3d coil opacity/.initial=1,
    3d coil opacity=1


    makeatletter % https://tex.stackexchange.com/a/219088/121799
    tikzsetget stroke color/.code=%
     expandafterglobal% Jump over, now we have global
     expandafterlet% Jump over now we have globallet
     expandafterpgfsavedstrokecolor% Jump we have globalletpgf...
     csnamestringcolor@pgfstrokecolorendcsname% Finally expand this and put it at the end 
     , % globalletpgf... in expanded form 
     restore stroke color/.code=pgf@setstrokecolor#1,

    defpgfpoint@onthreedcoil#1#2#3%
     pgf@x=#1pgfdecorationsegmentamplitude%
     pgf@x=pgfdecorationsegmentaspectpgf@x%
     pgf@y=#2pgfdecorationsegmentamplitude%
     pgf@xa=0.083333333333pgfdecorationsegmentlength%
     advancepgf@x by#3pgf@xa%
     advancepgf@x by-initialoffset pt%


    % coil decoration
    %
    % Parameters: pgfdecorationsegmentamplitude, pgfdecorationsegmentlength,

    pgfdeclaredecoration3d coilinitial
     
     stateinitial[width=0.25*pgfdecorationsegmentlength+pgfdecorationsegmentaspect*pgfdecorationsegmentamplitude,
     next state=coil, persistent precomputation=
     tikzsetget stroke color
     pgfmathsetmacroinitialoffset0.25*pgfdecorationsegmentlength+pgfdecorationsegmentaspect*pgfdecorationsegmentamplitude
     ]
     %
     pgfpathmovetopgfpointorigin 
     pgfsetstrokecolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfsetlinewidth1.5*TDCoilWidth 
     pgfpathcurveto
     pgfpoint@oncoil0 0.5551
     pgfpoint@oncoil0.445 1 2
     pgfpoint@oncoil1 1 3
     pgfusepathstroke
     pgfcoordinateTD@coilastpgfpoint@oncoil1 1 3 
     
     statecoil[switch if less than=%
     1.25pgfdecorationsegmentlength+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude to last,
     width=+pgfdecorationsegmentlength]
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfsetlinewidthTDCoilWidth 
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 4
     pgfpoint@onthreedcoil2 0.5555
     pgfpoint@onthreedcoil2 0 6
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     % 
     % draw the thick foreground path
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shfted -
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill % <- added
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil1 1 15 
     
     statelast[width=.25pgfdecorationsegmentlength+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude,next state=final]
     
     pgfsetstrokecolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfsetlinewidthTDCoilWidth
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 4
     pgfpoint@onthreedcoil2 0.5555
     pgfpoint@onthreedcoil2 0 6
     
     statefinal
     
     pgfpathlinetopgfpointdecoratedpathlast
     pgfusepathstroke
     tikzsetrestore stroke color/.expand once=pgfsavedstrokecolor
     

    makeatother

    begindocument
    begintikzpicture
    draw[decoration=3d coil color=blue,aspect=0.35, segment length=3.1mm, amplitude=3mm,3d coil,
    decorate] (0,0) -- (0,3);
    draw[decoration=3d coil color=red,3d coil opacity=0.9,aspect=0.45, segment length=3.1mm, amplitude=3mm,3d coil,
    decorate] (2,3) -- (2,0);
    draw[decoration=3d coil color=green!60!black,3d coil opacity=0.9,aspect=0.35, segment length=3.1mm, amplitude=3mm,3d coil,
    decorate] (4,3) to[out=0,in=90] (6,0);
    endtikzpicture
    enddocument


    FUN: The mandatory animation can be made with the same preamble + usepackagetikzmarmots and 



    begindocument
    foreach X [evaluate=X as Y using sin(X)]in 0,10,...,350

    begintikzpicture
    path[use as bounding box] (-1,-0.2) rectangle (1,4);
    draw[decoration=3d coil color=blue,aspect=0.35, segment
    length=(1.2+0.7*Y)*1mm, amplitude=3mm,3d coil,
    decorate] (0,0) -- (0,2);
    beginscope[shift=(-0.9,1+0.5*Y)]
    marmot[teeth,whiskers]
    endscope
    endtikzpicture
    enddocument


    enter image description here



    BONUS: A "complete" version, i.e. an analog of Jake's complete sines with a "closed" option (analogous to the closed zigzags.)



    documentclass[tikz,border=3.14mm]standalone
    usetikzlibrarydecorations.pathmorphing
    makeatletter
    newififcoil@closed
    pgfkeys%
    /pgf/decoration/.cd,
    3d coil color/.store in=TDCoilColor, 
    3d coil color/.initial=black,
    3d coil color=black,
    3d coil width/.store in=TDCoilWidth, 
    3d coil width/.initial=0.4pt,
    3d coil width=0.4pt,
    3d coil dist/.store in=TDCoilDist, 
    3d coil dist/.initial=0.6pt,
    3d coil dist=0.6pt,
    3d coil opacity/.store in=TDCoilOpacity, 
    3d coil opacity/.initial=1,
    3d coil opacity=1,
    3d coil closed/.code=coil@closedtrue


     % https://tex.stackexchange.com/a/219088/121799
    tikzsetget stroke color/.code=%
     expandafterglobal% Jump over, now we have global
     expandafterlet% Jump over now we have globallet
     expandafterpgfsavedstrokecolor% Jump we have globalletpgf...
     csnamestringcolor@pgfstrokecolorendcsname% Finally expand this and put it at the end 
     , % globalletpgf... in expanded form 
     restore stroke color/.code=pgf@setstrokecolor#1,

    defpgfpoint@onthreedcoil#1#2#3%
     pgf@x=#1pgfdecorationsegmentamplitude%
     pgf@x=pgfdecorationsegmentaspectpgf@x%
     pgf@y=#2pgfdecorationsegmentamplitude%
     pgf@xa=0.083333333333pgfdecorationsegmentlength%
     advancepgf@x by#3pgf@xa%
     advancepgf@x by-generaloffset pt%


    % coil decoration
    %
    % Parameters: pgfdecorationsegmentamplitude, pgfdecorationsegmentlength,

    pgfdeclaredecoration3d complete coilinitial
     
     stateinitial[width=0.5*pgfdecorationsegmentlength,
     next state=coil, persistent precomputation=% from https://tex.stackexchange.com/a/25689/121799
     pgfmathsetmacromatchinglengthpgfdecoratedinputsegmentlength / int(pgfdecoratedinputsegmentlength/pgfdecorationsegmentlength)
     setlengthpgfdecorationsegmentlengthmatchinglength pt
     tikzsetget stroke color
     pgfmathsetmacrogeneraloffsetpgfdecorationsegmentlength
     pgfmathsetmacroinitialoffset1.5*pgfdecorationsegmentlength
     pgfmathsetmacroauxoffset2.5*pgfdecorationsegmentlength
     ] 
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfsetlinewidthTDCoilWidth 
     ifcoil@closed
     begingroup
     defgeneraloffsetauxoffset
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18
     pgfcoordinateTD@coilfirstpgfpoint@onthreedcoil1 1 15
     pgfusepathstroke 
     pgfsetstrokecolorTDCoilColor
     endgroup
     fi
     begingroup %
     defgeneraloffsetinitialoffset
     ifcoil@closed
     pgfpathmovetopgfpointanchorTD@coilastcenter
     else
     pgfpathmovetopgfpointorigin
     fi
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     % 
     % draw the thick foreground path
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shfted -
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18 
     pgfusepathstroke 
     endgroup
     
     statecoil[switch if less than=%
     1.9*pgfdecorationsegmentlength to last,
     width=+pgfdecorationsegmentlength]
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfsetlinewidthTDCoilWidth 
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     % 
     % draw the thick foreground path
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shfted -
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     pgfusepathstroke 
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18 
     
     statelast[next state=final]
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfsetlinewidthTDCoilWidth 
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     % 
     % draw the thick foreground path
     %
     ifcoil@closed %pgfpointanchorTD@coilfirstcenter
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpointanchorTD@coilfirstcenter
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpointanchorTD@coilfirstcenter
     % draw the curve back shifted 
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     else
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shifted 
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     fi
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     ifcoil@closed %TD@coilfirst
     else
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     fi
     pgfusepathstroke 
     %pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18 
     
     statefinal
     
     pgfpathmovetopgfpointdecoratedpathlast
     tikzsetrestore stroke color/.expand once=pgfsavedstrokecolor
     

    makeatother

    begindocument
    begintikzpicture
    draw[decoration=3d coil color=red,aspect=0.35, segment length=3.1mm, 
    amplitude=3mm,3d complete coil,
    decorate] (0,1) -- (0,6);
    draw[decoration=3d coil color=blue,3d coil opacity=0.9,aspect=0.5, 
    segment length=2*pi*3cm/50, amplitude=5mm,3d complete coil,
    3d coil closed,
    decorate] (5,3.5) circle (3);
    draw[decoration=3d coil color=green!60!black,aspect=0.5, segment length=3.1mm, 
    amplitude=4mm,3d complete coil,
    decorate] (0,-1) -- (0,-6);
    draw[decoration=3d coil color=purple,3d coil opacity=0.9,aspect=0.5, 
    segment length=2*pi*3cm/50, amplitude=3mm,3d complete coil,
    3d coil closed,
    decorate] (5,-3.5) circle (3);
    endtikzpicture
    enddocument


    enter image description here






    share|improve this answer


















    • 3




      The decorations in pgf, it's the most difficult, wonderful work, bravo!
      – AndréC
      Sep 6 at 16:05










    • @AndréC Merci, but I am actually not really happy, What I would love to achieve is that it is not necessary to set the color, opacity and so on explicitly. And then there are more downsides. Assume I was able to achieve this, then the decomposition of the path in little segments has further downsides such as the fact that a dashed line will not look nice. So there is a lot of room for improvement...
      – marmot
      Sep 6 at 16:09










    • You can draw two lines that overlap when they are thin but then move away from each other on the thicker part so no step function in thickness LIkewise you can draw a white line on that is thicker on the top part so overlap is along path
      – joojaa
      Sep 6 at 16:30











    • @marmot its slightly less work. The strokes overlap anyway. So no particular reason to fill stuff except pedantry
      – joojaa
      Sep 6 at 16:40






    • 1




      Another beautiful piece of marmot magic!
      – Max
      Sep 7 at 18:04














    up vote
    45
    down vote













    The starting point of all this is the code in pgflibrarydecorations.pathmorphing.code.tex. I acknowledge a comment by joojaa that pointed out that the halo was not quite right in the original answers. I also appreciate a comment by Robert Harvey, who encouraged me to clean up. What I did is to modify the coil decoration of the decorations.pathmorphing library. There is still a lot of room for improvement. The keys in the beginning allow you to adjust the color, opacity, width of coil and additional width of the halo, I hope the names I gave to these parameters are self-explanatory.



    enter image description here



    documentclass[tikz,border=3.14mm]standalone
    usetikzlibrarydecorations.pathmorphing
    pgfkeys%
    /pgf/decoration/.cd,
    3d coil color/.store in=TDCoilColor, 
    3d coil color/.initial=black,
    3d coil color=black,
    3d coil width/.store in=TDCoilWidth, 
    3d coil width/.initial=0.4pt,
    3d coil width=0.4pt,
    3d coil dist/.store in=TDCoilDist, 
    3d coil dist/.initial=0.6pt,
    3d coil dist=0.6pt,
    3d coil opacity/.store in=TDCoilOpacity, 
    3d coil opacity/.initial=1,
    3d coil opacity=1


    makeatletter % https://tex.stackexchange.com/a/219088/121799
    tikzsetget stroke color/.code=%
     expandafterglobal% Jump over, now we have global
     expandafterlet% Jump over now we have globallet
     expandafterpgfsavedstrokecolor% Jump we have globalletpgf...
     csnamestringcolor@pgfstrokecolorendcsname% Finally expand this and put it at the end 
     , % globalletpgf... in expanded form 
     restore stroke color/.code=pgf@setstrokecolor#1,

    defpgfpoint@onthreedcoil#1#2#3%
     pgf@x=#1pgfdecorationsegmentamplitude%
     pgf@x=pgfdecorationsegmentaspectpgf@x%
     pgf@y=#2pgfdecorationsegmentamplitude%
     pgf@xa=0.083333333333pgfdecorationsegmentlength%
     advancepgf@x by#3pgf@xa%
     advancepgf@x by-initialoffset pt%


    % coil decoration
    %
    % Parameters: pgfdecorationsegmentamplitude, pgfdecorationsegmentlength,

    pgfdeclaredecoration3d coilinitial
     
     stateinitial[width=0.25*pgfdecorationsegmentlength+pgfdecorationsegmentaspect*pgfdecorationsegmentamplitude,
     next state=coil, persistent precomputation=
     tikzsetget stroke color
     pgfmathsetmacroinitialoffset0.25*pgfdecorationsegmentlength+pgfdecorationsegmentaspect*pgfdecorationsegmentamplitude
     ]
     %
     pgfpathmovetopgfpointorigin 
     pgfsetstrokecolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfsetlinewidth1.5*TDCoilWidth 
     pgfpathcurveto
     pgfpoint@oncoil0 0.5551
     pgfpoint@oncoil0.445 1 2
     pgfpoint@oncoil1 1 3
     pgfusepathstroke
     pgfcoordinateTD@coilastpgfpoint@oncoil1 1 3 
     
     statecoil[switch if less than=%
     1.25pgfdecorationsegmentlength+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude to last,
     width=+pgfdecorationsegmentlength]
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfsetlinewidthTDCoilWidth 
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 4
     pgfpoint@onthreedcoil2 0.5555
     pgfpoint@onthreedcoil2 0 6
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     % 
     % draw the thick foreground path
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shfted -
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill % <- added
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil1 1 15 
     
     statelast[width=.25pgfdecorationsegmentlength+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude,next state=final]
     
     pgfsetstrokecolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfsetlinewidthTDCoilWidth
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 4
     pgfpoint@onthreedcoil2 0.5555
     pgfpoint@onthreedcoil2 0 6
     
     statefinal
     
     pgfpathlinetopgfpointdecoratedpathlast
     pgfusepathstroke
     tikzsetrestore stroke color/.expand once=pgfsavedstrokecolor
     

    makeatother

    begindocument
    begintikzpicture
    draw[decoration=3d coil color=blue,aspect=0.35, segment length=3.1mm, amplitude=3mm,3d coil,
    decorate] (0,0) -- (0,3);
    draw[decoration=3d coil color=red,3d coil opacity=0.9,aspect=0.45, segment length=3.1mm, amplitude=3mm,3d coil,
    decorate] (2,3) -- (2,0);
    draw[decoration=3d coil color=green!60!black,3d coil opacity=0.9,aspect=0.35, segment length=3.1mm, amplitude=3mm,3d coil,
    decorate] (4,3) to[out=0,in=90] (6,0);
    endtikzpicture
    enddocument


    FUN: The mandatory animation can be made with the same preamble + usepackagetikzmarmots and 



    begindocument
    foreach X [evaluate=X as Y using sin(X)]in 0,10,...,350

    begintikzpicture
    path[use as bounding box] (-1,-0.2) rectangle (1,4);
    draw[decoration=3d coil color=blue,aspect=0.35, segment
    length=(1.2+0.7*Y)*1mm, amplitude=3mm,3d coil,
    decorate] (0,0) -- (0,2);
    beginscope[shift=(-0.9,1+0.5*Y)]
    marmot[teeth,whiskers]
    endscope
    endtikzpicture
    enddocument


    enter image description here



    BONUS: A "complete" version, i.e. an analog of Jake's complete sines with a "closed" option (analogous to the closed zigzags.)



    documentclass[tikz,border=3.14mm]standalone
    usetikzlibrarydecorations.pathmorphing
    makeatletter
    newififcoil@closed
    pgfkeys%
    /pgf/decoration/.cd,
    3d coil color/.store in=TDCoilColor, 
    3d coil color/.initial=black,
    3d coil color=black,
    3d coil width/.store in=TDCoilWidth, 
    3d coil width/.initial=0.4pt,
    3d coil width=0.4pt,
    3d coil dist/.store in=TDCoilDist, 
    3d coil dist/.initial=0.6pt,
    3d coil dist=0.6pt,
    3d coil opacity/.store in=TDCoilOpacity, 
    3d coil opacity/.initial=1,
    3d coil opacity=1,
    3d coil closed/.code=coil@closedtrue


     % https://tex.stackexchange.com/a/219088/121799
    tikzsetget stroke color/.code=%
     expandafterglobal% Jump over, now we have global
     expandafterlet% Jump over now we have globallet
     expandafterpgfsavedstrokecolor% Jump we have globalletpgf...
     csnamestringcolor@pgfstrokecolorendcsname% Finally expand this and put it at the end 
     , % globalletpgf... in expanded form 
     restore stroke color/.code=pgf@setstrokecolor#1,

    defpgfpoint@onthreedcoil#1#2#3%
     pgf@x=#1pgfdecorationsegmentamplitude%
     pgf@x=pgfdecorationsegmentaspectpgf@x%
     pgf@y=#2pgfdecorationsegmentamplitude%
     pgf@xa=0.083333333333pgfdecorationsegmentlength%
     advancepgf@x by#3pgf@xa%
     advancepgf@x by-generaloffset pt%


    % coil decoration
    %
    % Parameters: pgfdecorationsegmentamplitude, pgfdecorationsegmentlength,

    pgfdeclaredecoration3d complete coilinitial
     
     stateinitial[width=0.5*pgfdecorationsegmentlength,
     next state=coil, persistent precomputation=% from https://tex.stackexchange.com/a/25689/121799
     pgfmathsetmacromatchinglengthpgfdecoratedinputsegmentlength / int(pgfdecoratedinputsegmentlength/pgfdecorationsegmentlength)
     setlengthpgfdecorationsegmentlengthmatchinglength pt
     tikzsetget stroke color
     pgfmathsetmacrogeneraloffsetpgfdecorationsegmentlength
     pgfmathsetmacroinitialoffset1.5*pgfdecorationsegmentlength
     pgfmathsetmacroauxoffset2.5*pgfdecorationsegmentlength
     ] 
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfsetlinewidthTDCoilWidth 
     ifcoil@closed
     begingroup
     defgeneraloffsetauxoffset
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18
     pgfcoordinateTD@coilfirstpgfpoint@onthreedcoil1 1 15
     pgfusepathstroke 
     pgfsetstrokecolorTDCoilColor
     endgroup
     fi
     begingroup %
     defgeneraloffsetinitialoffset
     ifcoil@closed
     pgfpathmovetopgfpointanchorTD@coilastcenter
     else
     pgfpathmovetopgfpointorigin
     fi
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     % 
     % draw the thick foreground path
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shfted -
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18 
     pgfusepathstroke 
     endgroup
     
     statecoil[switch if less than=%
     1.9*pgfdecorationsegmentlength to last,
     width=+pgfdecorationsegmentlength]
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfsetlinewidthTDCoilWidth 
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     % 
     % draw the thick foreground path
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shfted -
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     pgfusepathstroke 
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18 
     
     statelast[next state=final]
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfsetlinewidthTDCoilWidth 
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     % 
     % draw the thick foreground path
     %
     ifcoil@closed %pgfpointanchorTD@coilfirstcenter
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpointanchorTD@coilfirstcenter
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpointanchorTD@coilfirstcenter
     % draw the curve back shifted 
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     else
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shifted 
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     fi
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     ifcoil@closed %TD@coilfirst
     else
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     fi
     pgfusepathstroke 
     %pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18 
     
     statefinal
     
     pgfpathmovetopgfpointdecoratedpathlast
     tikzsetrestore stroke color/.expand once=pgfsavedstrokecolor
     

    makeatother

    begindocument
    begintikzpicture
    draw[decoration=3d coil color=red,aspect=0.35, segment length=3.1mm, 
    amplitude=3mm,3d complete coil,
    decorate] (0,1) -- (0,6);
    draw[decoration=3d coil color=blue,3d coil opacity=0.9,aspect=0.5, 
    segment length=2*pi*3cm/50, amplitude=5mm,3d complete coil,
    3d coil closed,
    decorate] (5,3.5) circle (3);
    draw[decoration=3d coil color=green!60!black,aspect=0.5, segment length=3.1mm, 
    amplitude=4mm,3d complete coil,
    decorate] (0,-1) -- (0,-6);
    draw[decoration=3d coil color=purple,3d coil opacity=0.9,aspect=0.5, 
    segment length=2*pi*3cm/50, amplitude=3mm,3d complete coil,
    3d coil closed,
    decorate] (5,-3.5) circle (3);
    endtikzpicture
    enddocument


    enter image description here






    share|improve this answer


















    • 3




      The decorations in pgf, it's the most difficult, wonderful work, bravo!
      – AndréC
      Sep 6 at 16:05










    • @AndréC Merci, but I am actually not really happy, What I would love to achieve is that it is not necessary to set the color, opacity and so on explicitly. And then there are more downsides. Assume I was able to achieve this, then the decomposition of the path in little segments has further downsides such as the fact that a dashed line will not look nice. So there is a lot of room for improvement...
      – marmot
      Sep 6 at 16:09










    • You can draw two lines that overlap when they are thin but then move away from each other on the thicker part so no step function in thickness LIkewise you can draw a white line on that is thicker on the top part so overlap is along path
      – joojaa
      Sep 6 at 16:30











    • @marmot its slightly less work. The strokes overlap anyway. So no particular reason to fill stuff except pedantry
      – joojaa
      Sep 6 at 16:40






    • 1




      Another beautiful piece of marmot magic!
      – Max
      Sep 7 at 18:04












    up vote
    45
    down vote










    up vote
    45
    down vote









    The starting point of all this is the code in pgflibrarydecorations.pathmorphing.code.tex. I acknowledge a comment by joojaa that pointed out that the halo was not quite right in the original answers. I also appreciate a comment by Robert Harvey, who encouraged me to clean up. What I did is to modify the coil decoration of the decorations.pathmorphing library. There is still a lot of room for improvement. The keys in the beginning allow you to adjust the color, opacity, width of coil and additional width of the halo, I hope the names I gave to these parameters are self-explanatory.



    enter image description here



    documentclass[tikz,border=3.14mm]standalone
    usetikzlibrarydecorations.pathmorphing
    pgfkeys%
    /pgf/decoration/.cd,
    3d coil color/.store in=TDCoilColor, 
    3d coil color/.initial=black,
    3d coil color=black,
    3d coil width/.store in=TDCoilWidth, 
    3d coil width/.initial=0.4pt,
    3d coil width=0.4pt,
    3d coil dist/.store in=TDCoilDist, 
    3d coil dist/.initial=0.6pt,
    3d coil dist=0.6pt,
    3d coil opacity/.store in=TDCoilOpacity, 
    3d coil opacity/.initial=1,
    3d coil opacity=1


    makeatletter % https://tex.stackexchange.com/a/219088/121799
    tikzsetget stroke color/.code=%
     expandafterglobal% Jump over, now we have global
     expandafterlet% Jump over now we have globallet
     expandafterpgfsavedstrokecolor% Jump we have globalletpgf...
     csnamestringcolor@pgfstrokecolorendcsname% Finally expand this and put it at the end 
     , % globalletpgf... in expanded form 
     restore stroke color/.code=pgf@setstrokecolor#1,

    defpgfpoint@onthreedcoil#1#2#3%
     pgf@x=#1pgfdecorationsegmentamplitude%
     pgf@x=pgfdecorationsegmentaspectpgf@x%
     pgf@y=#2pgfdecorationsegmentamplitude%
     pgf@xa=0.083333333333pgfdecorationsegmentlength%
     advancepgf@x by#3pgf@xa%
     advancepgf@x by-initialoffset pt%


    % coil decoration
    %
    % Parameters: pgfdecorationsegmentamplitude, pgfdecorationsegmentlength,

    pgfdeclaredecoration3d coilinitial
     
     stateinitial[width=0.25*pgfdecorationsegmentlength+pgfdecorationsegmentaspect*pgfdecorationsegmentamplitude,
     next state=coil, persistent precomputation=
     tikzsetget stroke color
     pgfmathsetmacroinitialoffset0.25*pgfdecorationsegmentlength+pgfdecorationsegmentaspect*pgfdecorationsegmentamplitude
     ]
     %
     pgfpathmovetopgfpointorigin 
     pgfsetstrokecolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfsetlinewidth1.5*TDCoilWidth 
     pgfpathcurveto
     pgfpoint@oncoil0 0.5551
     pgfpoint@oncoil0.445 1 2
     pgfpoint@oncoil1 1 3
     pgfusepathstroke
     pgfcoordinateTD@coilastpgfpoint@oncoil1 1 3 
     
     statecoil[switch if less than=%
     1.25pgfdecorationsegmentlength+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude to last,
     width=+pgfdecorationsegmentlength]
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfsetlinewidthTDCoilWidth 
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 4
     pgfpoint@onthreedcoil2 0.5555
     pgfpoint@onthreedcoil2 0 6
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     % 
     % draw the thick foreground path
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shfted -
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill % <- added
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil1 1 15 
     
     statelast[width=.25pgfdecorationsegmentlength+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude,next state=final]
     
     pgfsetstrokecolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfsetlinewidthTDCoilWidth
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 4
     pgfpoint@onthreedcoil2 0.5555
     pgfpoint@onthreedcoil2 0 6
     
     statefinal
     
     pgfpathlinetopgfpointdecoratedpathlast
     pgfusepathstroke
     tikzsetrestore stroke color/.expand once=pgfsavedstrokecolor
     

    makeatother

    begindocument
    begintikzpicture
    draw[decoration=3d coil color=blue,aspect=0.35, segment length=3.1mm, amplitude=3mm,3d coil,
    decorate] (0,0) -- (0,3);
    draw[decoration=3d coil color=red,3d coil opacity=0.9,aspect=0.45, segment length=3.1mm, amplitude=3mm,3d coil,
    decorate] (2,3) -- (2,0);
    draw[decoration=3d coil color=green!60!black,3d coil opacity=0.9,aspect=0.35, segment length=3.1mm, amplitude=3mm,3d coil,
    decorate] (4,3) to[out=0,in=90] (6,0);
    endtikzpicture
    enddocument


    FUN: The mandatory animation can be made with the same preamble + usepackagetikzmarmots and 



    begindocument
    foreach X [evaluate=X as Y using sin(X)]in 0,10,...,350

    begintikzpicture
    path[use as bounding box] (-1,-0.2) rectangle (1,4);
    draw[decoration=3d coil color=blue,aspect=0.35, segment
    length=(1.2+0.7*Y)*1mm, amplitude=3mm,3d coil,
    decorate] (0,0) -- (0,2);
    beginscope[shift=(-0.9,1+0.5*Y)]
    marmot[teeth,whiskers]
    endscope
    endtikzpicture
    enddocument


    enter image description here



    BONUS: A "complete" version, i.e. an analog of Jake's complete sines with a "closed" option (analogous to the closed zigzags.)



    documentclass[tikz,border=3.14mm]standalone
    usetikzlibrarydecorations.pathmorphing
    makeatletter
    newififcoil@closed
    pgfkeys%
    /pgf/decoration/.cd,
    3d coil color/.store in=TDCoilColor, 
    3d coil color/.initial=black,
    3d coil color=black,
    3d coil width/.store in=TDCoilWidth, 
    3d coil width/.initial=0.4pt,
    3d coil width=0.4pt,
    3d coil dist/.store in=TDCoilDist, 
    3d coil dist/.initial=0.6pt,
    3d coil dist=0.6pt,
    3d coil opacity/.store in=TDCoilOpacity, 
    3d coil opacity/.initial=1,
    3d coil opacity=1,
    3d coil closed/.code=coil@closedtrue


     % https://tex.stackexchange.com/a/219088/121799
    tikzsetget stroke color/.code=%
     expandafterglobal% Jump over, now we have global
     expandafterlet% Jump over now we have globallet
     expandafterpgfsavedstrokecolor% Jump we have globalletpgf...
     csnamestringcolor@pgfstrokecolorendcsname% Finally expand this and put it at the end 
     , % globalletpgf... in expanded form 
     restore stroke color/.code=pgf@setstrokecolor#1,

    defpgfpoint@onthreedcoil#1#2#3%
     pgf@x=#1pgfdecorationsegmentamplitude%
     pgf@x=pgfdecorationsegmentaspectpgf@x%
     pgf@y=#2pgfdecorationsegmentamplitude%
     pgf@xa=0.083333333333pgfdecorationsegmentlength%
     advancepgf@x by#3pgf@xa%
     advancepgf@x by-generaloffset pt%


    % coil decoration
    %
    % Parameters: pgfdecorationsegmentamplitude, pgfdecorationsegmentlength,

    pgfdeclaredecoration3d complete coilinitial
     
     stateinitial[width=0.5*pgfdecorationsegmentlength,
     next state=coil, persistent precomputation=% from https://tex.stackexchange.com/a/25689/121799
     pgfmathsetmacromatchinglengthpgfdecoratedinputsegmentlength / int(pgfdecoratedinputsegmentlength/pgfdecorationsegmentlength)
     setlengthpgfdecorationsegmentlengthmatchinglength pt
     tikzsetget stroke color
     pgfmathsetmacrogeneraloffsetpgfdecorationsegmentlength
     pgfmathsetmacroinitialoffset1.5*pgfdecorationsegmentlength
     pgfmathsetmacroauxoffset2.5*pgfdecorationsegmentlength
     ] 
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfsetlinewidthTDCoilWidth 
     ifcoil@closed
     begingroup
     defgeneraloffsetauxoffset
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18
     pgfcoordinateTD@coilfirstpgfpoint@onthreedcoil1 1 15
     pgfusepathstroke 
     pgfsetstrokecolorTDCoilColor
     endgroup
     fi
     begingroup %
     defgeneraloffsetinitialoffset
     ifcoil@closed
     pgfpathmovetopgfpointanchorTD@coilastcenter
     else
     pgfpathmovetopgfpointorigin
     fi
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     % 
     % draw the thick foreground path
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shfted -
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18 
     pgfusepathstroke 
     endgroup
     
     statecoil[switch if less than=%
     1.9*pgfdecorationsegmentlength to last,
     width=+pgfdecorationsegmentlength]
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfsetlinewidthTDCoilWidth 
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     % 
     % draw the thick foreground path
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shfted -
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     pgfusepathstroke 
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18 
     
     statelast[next state=final]
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfsetlinewidthTDCoilWidth 
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     % 
     % draw the thick foreground path
     %
     ifcoil@closed %pgfpointanchorTD@coilfirstcenter
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpointanchorTD@coilfirstcenter
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpointanchorTD@coilfirstcenter
     % draw the curve back shifted 
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     else
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shifted 
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     fi
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     ifcoil@closed %TD@coilfirst
     else
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     fi
     pgfusepathstroke 
     %pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18 
     
     statefinal
     
     pgfpathmovetopgfpointdecoratedpathlast
     tikzsetrestore stroke color/.expand once=pgfsavedstrokecolor
     

    makeatother

    begindocument
    begintikzpicture
    draw[decoration=3d coil color=red,aspect=0.35, segment length=3.1mm, 
    amplitude=3mm,3d complete coil,
    decorate] (0,1) -- (0,6);
    draw[decoration=3d coil color=blue,3d coil opacity=0.9,aspect=0.5, 
    segment length=2*pi*3cm/50, amplitude=5mm,3d complete coil,
    3d coil closed,
    decorate] (5,3.5) circle (3);
    draw[decoration=3d coil color=green!60!black,aspect=0.5, segment length=3.1mm, 
    amplitude=4mm,3d complete coil,
    decorate] (0,-1) -- (0,-6);
    draw[decoration=3d coil color=purple,3d coil opacity=0.9,aspect=0.5, 
    segment length=2*pi*3cm/50, amplitude=3mm,3d complete coil,
    3d coil closed,
    decorate] (5,-3.5) circle (3);
    endtikzpicture
    enddocument


    enter image description here






    share|improve this answer














    The starting point of all this is the code in pgflibrarydecorations.pathmorphing.code.tex. I acknowledge a comment by joojaa that pointed out that the halo was not quite right in the original answers. I also appreciate a comment by Robert Harvey, who encouraged me to clean up. What I did is to modify the coil decoration of the decorations.pathmorphing library. There is still a lot of room for improvement. The keys in the beginning allow you to adjust the color, opacity, width of coil and additional width of the halo, I hope the names I gave to these parameters are self-explanatory.



    enter image description here



    documentclass[tikz,border=3.14mm]standalone
    usetikzlibrarydecorations.pathmorphing
    pgfkeys%
    /pgf/decoration/.cd,
    3d coil color/.store in=TDCoilColor, 
    3d coil color/.initial=black,
    3d coil color=black,
    3d coil width/.store in=TDCoilWidth, 
    3d coil width/.initial=0.4pt,
    3d coil width=0.4pt,
    3d coil dist/.store in=TDCoilDist, 
    3d coil dist/.initial=0.6pt,
    3d coil dist=0.6pt,
    3d coil opacity/.store in=TDCoilOpacity, 
    3d coil opacity/.initial=1,
    3d coil opacity=1


    makeatletter % https://tex.stackexchange.com/a/219088/121799
    tikzsetget stroke color/.code=%
     expandafterglobal% Jump over, now we have global
     expandafterlet% Jump over now we have globallet
     expandafterpgfsavedstrokecolor% Jump we have globalletpgf...
     csnamestringcolor@pgfstrokecolorendcsname% Finally expand this and put it at the end 
     , % globalletpgf... in expanded form 
     restore stroke color/.code=pgf@setstrokecolor#1,

    defpgfpoint@onthreedcoil#1#2#3%
     pgf@x=#1pgfdecorationsegmentamplitude%
     pgf@x=pgfdecorationsegmentaspectpgf@x%
     pgf@y=#2pgfdecorationsegmentamplitude%
     pgf@xa=0.083333333333pgfdecorationsegmentlength%
     advancepgf@x by#3pgf@xa%
     advancepgf@x by-initialoffset pt%


    % coil decoration
    %
    % Parameters: pgfdecorationsegmentamplitude, pgfdecorationsegmentlength,

    pgfdeclaredecoration3d coilinitial
     
     stateinitial[width=0.25*pgfdecorationsegmentlength+pgfdecorationsegmentaspect*pgfdecorationsegmentamplitude,
     next state=coil, persistent precomputation=
     tikzsetget stroke color
     pgfmathsetmacroinitialoffset0.25*pgfdecorationsegmentlength+pgfdecorationsegmentaspect*pgfdecorationsegmentamplitude
     ]
     %
     pgfpathmovetopgfpointorigin 
     pgfsetstrokecolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfsetlinewidth1.5*TDCoilWidth 
     pgfpathcurveto
     pgfpoint@oncoil0 0.5551
     pgfpoint@oncoil0.445 1 2
     pgfpoint@oncoil1 1 3
     pgfusepathstroke
     pgfcoordinateTD@coilastpgfpoint@oncoil1 1 3 
     
     statecoil[switch if less than=%
     1.25pgfdecorationsegmentlength+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude to last,
     width=+pgfdecorationsegmentlength]
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfsetlinewidthTDCoilWidth 
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 4
     pgfpoint@onthreedcoil2 0.5555
     pgfpoint@onthreedcoil2 0 6
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     % 
     % draw the thick foreground path
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shfted -
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill % <- added
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil1 1 15 
     
     statelast[width=.25pgfdecorationsegmentlength+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude+%
     pgfdecorationsegmentaspectpgfdecorationsegmentamplitude,next state=final]
     
     pgfsetstrokecolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfsetlinewidthTDCoilWidth
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 4
     pgfpoint@onthreedcoil2 0.5555
     pgfpoint@onthreedcoil2 0 6
     
     statefinal
     
     pgfpathlinetopgfpointdecoratedpathlast
     pgfusepathstroke
     tikzsetrestore stroke color/.expand once=pgfsavedstrokecolor
     

    makeatother

    begindocument
    begintikzpicture
    draw[decoration=3d coil color=blue,aspect=0.35, segment length=3.1mm, amplitude=3mm,3d coil,
    decorate] (0,0) -- (0,3);
    draw[decoration=3d coil color=red,3d coil opacity=0.9,aspect=0.45, segment length=3.1mm, amplitude=3mm,3d coil,
    decorate] (2,3) -- (2,0);
    draw[decoration=3d coil color=green!60!black,3d coil opacity=0.9,aspect=0.35, segment length=3.1mm, amplitude=3mm,3d coil,
    decorate] (4,3) to[out=0,in=90] (6,0);
    endtikzpicture
    enddocument


    FUN: The mandatory animation can be made with the same preamble + usepackagetikzmarmots and 



    begindocument
    foreach X [evaluate=X as Y using sin(X)]in 0,10,...,350

    begintikzpicture
    path[use as bounding box] (-1,-0.2) rectangle (1,4);
    draw[decoration=3d coil color=blue,aspect=0.35, segment
    length=(1.2+0.7*Y)*1mm, amplitude=3mm,3d coil,
    decorate] (0,0) -- (0,2);
    beginscope[shift=(-0.9,1+0.5*Y)]
    marmot[teeth,whiskers]
    endscope
    endtikzpicture
    enddocument


    enter image description here



    BONUS: A "complete" version, i.e. an analog of Jake's complete sines with a "closed" option (analogous to the closed zigzags.)



    documentclass[tikz,border=3.14mm]standalone
    usetikzlibrarydecorations.pathmorphing
    makeatletter
    newififcoil@closed
    pgfkeys%
    /pgf/decoration/.cd,
    3d coil color/.store in=TDCoilColor, 
    3d coil color/.initial=black,
    3d coil color=black,
    3d coil width/.store in=TDCoilWidth, 
    3d coil width/.initial=0.4pt,
    3d coil width=0.4pt,
    3d coil dist/.store in=TDCoilDist, 
    3d coil dist/.initial=0.6pt,
    3d coil dist=0.6pt,
    3d coil opacity/.store in=TDCoilOpacity, 
    3d coil opacity/.initial=1,
    3d coil opacity=1,
    3d coil closed/.code=coil@closedtrue


     % https://tex.stackexchange.com/a/219088/121799
    tikzsetget stroke color/.code=%
     expandafterglobal% Jump over, now we have global
     expandafterlet% Jump over now we have globallet
     expandafterpgfsavedstrokecolor% Jump we have globalletpgf...
     csnamestringcolor@pgfstrokecolorendcsname% Finally expand this and put it at the end 
     , % globalletpgf... in expanded form 
     restore stroke color/.code=pgf@setstrokecolor#1,

    defpgfpoint@onthreedcoil#1#2#3%
     pgf@x=#1pgfdecorationsegmentamplitude%
     pgf@x=pgfdecorationsegmentaspectpgf@x%
     pgf@y=#2pgfdecorationsegmentamplitude%
     pgf@xa=0.083333333333pgfdecorationsegmentlength%
     advancepgf@x by#3pgf@xa%
     advancepgf@x by-generaloffset pt%


    % coil decoration
    %
    % Parameters: pgfdecorationsegmentamplitude, pgfdecorationsegmentlength,

    pgfdeclaredecoration3d complete coilinitial
     
     stateinitial[width=0.5*pgfdecorationsegmentlength,
     next state=coil, persistent precomputation=% from https://tex.stackexchange.com/a/25689/121799
     pgfmathsetmacromatchinglengthpgfdecoratedinputsegmentlength / int(pgfdecoratedinputsegmentlength/pgfdecorationsegmentlength)
     setlengthpgfdecorationsegmentlengthmatchinglength pt
     tikzsetget stroke color
     pgfmathsetmacrogeneraloffsetpgfdecorationsegmentlength
     pgfmathsetmacroinitialoffset1.5*pgfdecorationsegmentlength
     pgfmathsetmacroauxoffset2.5*pgfdecorationsegmentlength
     ] 
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfsetlinewidthTDCoilWidth 
     ifcoil@closed
     begingroup
     defgeneraloffsetauxoffset
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18
     pgfcoordinateTD@coilfirstpgfpoint@onthreedcoil1 1 15
     pgfusepathstroke 
     pgfsetstrokecolorTDCoilColor
     endgroup
     fi
     begingroup %
     defgeneraloffsetinitialoffset
     ifcoil@closed
     pgfpathmovetopgfpointanchorTD@coilastcenter
     else
     pgfpathmovetopgfpointorigin
     fi
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     % 
     % draw the thick foreground path
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shfted -
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18 
     pgfusepathstroke 
     endgroup
     
     statecoil[switch if less than=%
     1.9*pgfdecorationsegmentlength to last,
     width=+pgfdecorationsegmentlength]
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfsetlinewidthTDCoilWidth 
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     % 
     % draw the thick foreground path
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shfted -
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     pgfusepathstroke 
     pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18 
     
     statelast[next state=final]
     % line in the back
     %
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpointanchorTD@coilastcenter
     pgfsetlinewidthTDCoilWidth 
     pgfpathcurveto
     pgfpoint@onthreedcoil2 -0.5557
     pgfpoint@onthreedcoil1.555-1 8
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke 
     % 
     % draw the thick foreground path
     %
     ifcoil@closed %pgfpointanchorTD@coilfirstcenter
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpointanchorTD@coilfirstcenter
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpointanchorTD@coilfirstcenter
     % draw the curve back shifted 
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     else
     %
     % white background for front thick part
     %
     pgfsetstrokeopacity1
     pgfsetstrokecolorwhite
     pgfsetfillcolorwhite
     pgfsetlinewidth1.5*TDCoilWidth+1.5*TDCoilDist
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     % draw forward
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     pgfsetstrokecolorTDCoilColor
     pgfsetfillcolorTDCoilColor
     pgfsetstrokeopacityTDCoilOpacity
     pgfpathmovetopgfpoint@onthreedcoil1 1 3
     pgfsetlinewidthTDCoilWidth 
     % forward shifted +
     pgfpathmovetopgfpoint@onthreedcoil1 -1 9
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil0 -0.55511.25
     pgfpoint@onthreedcoil0 0 12.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 0.55513.25
     pgfpoint@onthreedcoil0.445 1 14.25
     pgfpoint@onthreedcoil1 1 15
     % draw the curve back shifted 
     pgfpathcurveto
     pgfpoint@onthreedcoil0.445 1 14
     pgfpoint@onthreedcoil0 0.55512.75
     pgfpoint@onthreedcoil0 0 11.5
     pgfpathcurveto
     pgfpoint@onthreedcoil0 -0.55510.75
     pgfpoint@onthreedcoil0.445-1 10
     pgfpoint@onthreedcoil1 -1 9
     pgfusepathstroke,fill 
     fi
     pgfpathmovetopgfpoint@onthreedcoil1 1 15
     ifcoil@closed %TD@coilfirst
     else
     pgfpathcurveto
     pgfpoint@onthreedcoil1.555 1 16
     pgfpoint@onthreedcoil2 0.55517
     pgfpoint@onthreedcoil2 0 18
     fi
     pgfusepathstroke 
     %pgfcoordinateTD@coilastpgfpoint@onthreedcoil2 0 18 
     
     statefinal
     
     pgfpathmovetopgfpointdecoratedpathlast
     tikzsetrestore stroke color/.expand once=pgfsavedstrokecolor
     

    makeatother

    begindocument
    begintikzpicture
    draw[decoration=3d coil color=red,aspect=0.35, segment length=3.1mm, 
    amplitude=3mm,3d complete coil,
    decorate] (0,1) -- (0,6);
    draw[decoration=3d coil color=blue,3d coil opacity=0.9,aspect=0.5, 
    segment length=2*pi*3cm/50, amplitude=5mm,3d complete coil,
    3d coil closed,
    decorate] (5,3.5) circle (3);
    draw[decoration=3d coil color=green!60!black,aspect=0.5, segment length=3.1mm, 
    amplitude=4mm,3d complete coil,
    decorate] (0,-1) -- (0,-6);
    draw[decoration=3d coil color=purple,3d coil opacity=0.9,aspect=0.5, 
    segment length=2*pi*3cm/50, amplitude=3mm,3d complete coil,
    3d coil closed,
    decorate] (5,-3.5) circle (3);
    endtikzpicture
    enddocument


    enter image description here







    share|improve this answer














    share|improve this answer



    share|improve this answer








    edited Sep 8 at 16:54

























    answered Sep 6 at 14:07









    marmot

    58.8k463126




    58.8k463126







    • 3




      The decorations in pgf, it's the most difficult, wonderful work, bravo!
      – AndréC
      Sep 6 at 16:05










    • @AndréC Merci, but I am actually not really happy, What I would love to achieve is that it is not necessary to set the color, opacity and so on explicitly. And then there are more downsides. Assume I was able to achieve this, then the decomposition of the path in little segments has further downsides such as the fact that a dashed line will not look nice. So there is a lot of room for improvement...
      – marmot
      Sep 6 at 16:09










    • You can draw two lines that overlap when they are thin but then move away from each other on the thicker part so no step function in thickness LIkewise you can draw a white line on that is thicker on the top part so overlap is along path
      – joojaa
      Sep 6 at 16:30











    • @marmot its slightly less work. The strokes overlap anyway. So no particular reason to fill stuff except pedantry
      – joojaa
      Sep 6 at 16:40






    • 1




      Another beautiful piece of marmot magic!
      – Max
      Sep 7 at 18:04












    • 3




      The decorations in pgf, it's the most difficult, wonderful work, bravo!
      – AndréC
      Sep 6 at 16:05










    • @AndréC Merci, but I am actually not really happy, What I would love to achieve is that it is not necessary to set the color, opacity and so on explicitly. And then there are more downsides. Assume I was able to achieve this, then the decomposition of the path in little segments has further downsides such as the fact that a dashed line will not look nice. So there is a lot of room for improvement...
      – marmot
      Sep 6 at 16:09










    • You can draw two lines that overlap when they are thin but then move away from each other on the thicker part so no step function in thickness LIkewise you can draw a white line on that is thicker on the top part so overlap is along path
      – joojaa
      Sep 6 at 16:30











    • @marmot its slightly less work. The strokes overlap anyway. So no particular reason to fill stuff except pedantry
      – joojaa
      Sep 6 at 16:40






    • 1




      Another beautiful piece of marmot magic!
      – Max
      Sep 7 at 18:04







    3




    3




    The decorations in pgf, it's the most difficult, wonderful work, bravo!
    – AndréC
    Sep 6 at 16:05




    The decorations in pgf, it's the most difficult, wonderful work, bravo!
    – AndréC
    Sep 6 at 16:05












    @AndréC Merci, but I am actually not really happy, What I would love to achieve is that it is not necessary to set the color, opacity and so on explicitly. And then there are more downsides. Assume I was able to achieve this, then the decomposition of the path in little segments has further downsides such as the fact that a dashed line will not look nice. So there is a lot of room for improvement...
    – marmot
    Sep 6 at 16:09




    @AndréC Merci, but I am actually not really happy, What I would love to achieve is that it is not necessary to set the color, opacity and so on explicitly. And then there are more downsides. Assume I was able to achieve this, then the decomposition of the path in little segments has further downsides such as the fact that a dashed line will not look nice. So there is a lot of room for improvement...
    – marmot
    Sep 6 at 16:09












    You can draw two lines that overlap when they are thin but then move away from each other on the thicker part so no step function in thickness LIkewise you can draw a white line on that is thicker on the top part so overlap is along path
    – joojaa
    Sep 6 at 16:30





    You can draw two lines that overlap when they are thin but then move away from each other on the thicker part so no step function in thickness LIkewise you can draw a white line on that is thicker on the top part so overlap is along path
    – joojaa
    Sep 6 at 16:30













    @marmot its slightly less work. The strokes overlap anyway. So no particular reason to fill stuff except pedantry
    – joojaa
    Sep 6 at 16:40




    @marmot its slightly less work. The strokes overlap anyway. So no particular reason to fill stuff except pedantry
    – joojaa
    Sep 6 at 16:40




    1




    1




    Another beautiful piece of marmot magic!
    – Max
    Sep 7 at 18:04




    Another beautiful piece of marmot magic!
    – Max
    Sep 7 at 18:04










    up vote
    23
    down vote













    If you put negative values for aspect and amplitude, you can get the mirrored coil, add this in the @marmot's answer may complete the desired output; also I added an option using markings to get some similar drawing that uses scope and yscale to invert the marking, then a new variable to control the coil color,when the path is straight it has good result, markings path lacks bending good results.



    EDIT: Added a control for marking step to improve bending results.



    RESULT:



    enter image description here



    MWE:



    documentclass[tikz,border=20pt]standalone
    usetikzlibrarydecorations.pathmorphing,decorations.markings

    begindocument

    begintikzpicture[
     CoilColor/.store in=coilcolor,CoilColor=black,
     Step/.store in=Step,Step=0.1,
     Coil/.style=
     double=black,
     draw=gray!50,
     decoration=
     #1,
     segment length=3mm,
     coil
     ,
     decorate,
     ,
     Coil2/.style=
     decorate,
     decoration=
     markings,
     mark= between positions 0 and 1 step Step
     with 
     beginscope[yscale=#1]
     draw[xshift=9.2,fill,coilcolor!70!black]
     (0,0)++(-135: 0.2 and 0.4) 
     .. controls +(-0.2,0) and +(-0.3,0) .. (90: 0.2 and 0.4)
     .. controls +(-0.33,0) and +(-0.23,0) .. (-135: 0.2 and 0.4); 
     draw[white,line width=2pt]
     (0,0)++(90: 0.2 and 0.4) 
     .. controls +(0.3,0) and +(0.2,0) .. (-45: 0.2 and 0.4);
     draw[fill=coilcolor,coilcolor]
     (0,0)++(90: 0.2 and 0.4) 
     .. controls +(0.3,0) and +(0.2,0) .. (-45: 0.2 and 0.4)
     .. controls +(0.25,0) and +(0.35,0) .. (90: 0.2 and 0.4);
     endscope 
     
     
     
    ]
    draw[Coil=aspect=-0.3,amplitude=-3mm,blue] (0,0) -- ++ (0,-3);
    draw[Coil=aspect=0.3,amplitude=3mm,red] (1.5,0) -- ++ (0,-3);
    draw[Coil=aspect=0.3,amplitude=3mm,green!50!black] (3,0) arc (90:0:3);
    draw[Coil=aspect=-0.3,amplitude=-3mm] (3,1) arc (90:0:4);

    draw[Coil2=-1,CoilColor=blue] (0,-4) -- ++ (0,-3);
    draw[Coil2=1,CoilColor=red] (1.5,-4) -- ++ (0,-3);
    draw[Coil2=-1,CoilColor=green!50!black,Step=0.065] (3,-4) arc (90:0:3);
    draw[Coil2=1,Step=0.048] (3,-3) arc (90:0:4);

    endtikzpicture
    enddocument


    UPDATE:
    Acording to @marmot's suggestion closing the gaps and drawing all the variations, using pgfdecoratedpathlength, /pgf/decoration/mark info/sequence number.



    RESULT:
    enter image description here



    MWE:



    documentclass[tikz,border=20pt]standalone
    usetikzlibrarydecorations.markings

    begindocument

    begintikzpicture[
     CoilColor/.store in=coilcolor,CoilColor=black,
     Step/.store in=Step,Step=0.1,
     Width/.store in=Width,Width=0.4,
     Coil2/.style=
     decorate,
     decoration=
     markings,
     mark= between positions 0 and 1 step Step 
     with 
     beginscope[yscale=#1]
     pgfmathparseint(pgfdecoratedpathlength/28.45*100*Step)
     edefHightpgfmathresult
     ifnumpgfkeysvalueof/pgf/decoration/mark info/sequence number=1
     path (0,0)++(90: Hight/200 and Width) coordinate (b);
     fi
     ifnumpgfkeysvalueof/pgf/decoration/mark info/sequence number>1
     coordinate (b) at (d);
     fi
     path (b) arc (90:-135: Hight/200 and Width) coordinate (a);
     path (b) arc (90:-45: Hight/200 and Width) coordinate (c);
     path (b)++(Hight/100,0) coordinate (d);
     draw[fill,coilcolor!70!black]
     (c)
     .. controls +(-0.175,0) and +(-0.275,0) .. (d)
     .. controls +(-0.325,0) and +(-0.225,0) .. (c);
     draw[white,line width=2pt]
     (b)
     .. controls +(0.3,0) and +(0.2,0) .. (c);
     draw[fill,coilcolor]
     (b)
     .. controls +(0.275,0) and +(0.175,0) .. (c)
     .. controls +(0.225,0) and +(0.325,0) .. (b);
     endscope
     
     
     
    ]

    draw[Coil2=-1,CoilColor=red,Step=0.15] (0.5,0) -- ++ (0,-3);
    draw[Coil2=1.5,CoilColor=magenta] (1.5,0) -- ++ (0,-3);

    draw[Coil2=1,CoilColor=green!70!black,Step=0.02] (0,-4) 
     to [in=90,out=0] ++(2.5,-1)
     to [in=180,out=-90] ++(2.5,-1)
     to [in=-90,out=0] ++(2,1.5)
     to [in=-90,out=90] ++(0.5,3) arc (0:90:2);

    draw[Coil2=-1,CoilColor=green!50!cyan,Step=0.02] (0,-5) 
     to [in=90,out=0] ++(1.5,-1)
     to [in=180,out=-90] ++(4,-1)
     to [in=-90,out=0] ++(3,2.5)
     to [in=-90,out=90] ++(0.5,4.5) arc (0:90:2);

    draw[Coil2=1,CoilColor=cyan!30!blue,Step=0.05] (5.7,-2) arc (360:0:1.5);
    draw[Coil2=-1,CoilColor=cyan!70!blue,Step=0.05] (6.5,-2) arc (360:0:1.5);

    endtikzpicture
    enddocument





    share|improve this answer


























      up vote
      23
      down vote













      If you put negative values for aspect and amplitude, you can get the mirrored coil, add this in the @marmot's answer may complete the desired output; also I added an option using markings to get some similar drawing that uses scope and yscale to invert the marking, then a new variable to control the coil color,when the path is straight it has good result, markings path lacks bending good results.



      EDIT: Added a control for marking step to improve bending results.



      RESULT:



      enter image description here



      MWE:



      documentclass[tikz,border=20pt]standalone
      usetikzlibrarydecorations.pathmorphing,decorations.markings

      begindocument

      begintikzpicture[
       CoilColor/.store in=coilcolor,CoilColor=black,
       Step/.store in=Step,Step=0.1,
       Coil/.style=
       double=black,
       draw=gray!50,
       decoration=
       #1,
       segment length=3mm,
       coil
       ,
       decorate,
       ,
       Coil2/.style=
       decorate,
       decoration=
       markings,
       mark= between positions 0 and 1 step Step
       with 
       beginscope[yscale=#1]
       draw[xshift=9.2,fill,coilcolor!70!black]
       (0,0)++(-135: 0.2 and 0.4) 
       .. controls +(-0.2,0) and +(-0.3,0) .. (90: 0.2 and 0.4)
       .. controls +(-0.33,0) and +(-0.23,0) .. (-135: 0.2 and 0.4); 
       draw[white,line width=2pt]
       (0,0)++(90: 0.2 and 0.4) 
       .. controls +(0.3,0) and +(0.2,0) .. (-45: 0.2 and 0.4);
       draw[fill=coilcolor,coilcolor]
       (0,0)++(90: 0.2 and 0.4) 
       .. controls +(0.3,0) and +(0.2,0) .. (-45: 0.2 and 0.4)
       .. controls +(0.25,0) and +(0.35,0) .. (90: 0.2 and 0.4);
       endscope 
       
       
       
      ]
      draw[Coil=aspect=-0.3,amplitude=-3mm,blue] (0,0) -- ++ (0,-3);
      draw[Coil=aspect=0.3,amplitude=3mm,red] (1.5,0) -- ++ (0,-3);
      draw[Coil=aspect=0.3,amplitude=3mm,green!50!black] (3,0) arc (90:0:3);
      draw[Coil=aspect=-0.3,amplitude=-3mm] (3,1) arc (90:0:4);

      draw[Coil2=-1,CoilColor=blue] (0,-4) -- ++ (0,-3);
      draw[Coil2=1,CoilColor=red] (1.5,-4) -- ++ (0,-3);
      draw[Coil2=-1,CoilColor=green!50!black,Step=0.065] (3,-4) arc (90:0:3);
      draw[Coil2=1,Step=0.048] (3,-3) arc (90:0:4);

      endtikzpicture
      enddocument


      UPDATE:
      Acording to @marmot's suggestion closing the gaps and drawing all the variations, using pgfdecoratedpathlength, /pgf/decoration/mark info/sequence number.



      RESULT:
      enter image description here



      MWE:



      documentclass[tikz,border=20pt]standalone
      usetikzlibrarydecorations.markings

      begindocument

      begintikzpicture[
       CoilColor/.store in=coilcolor,CoilColor=black,
       Step/.store in=Step,Step=0.1,
       Width/.store in=Width,Width=0.4,
       Coil2/.style=
       decorate,
       decoration=
       markings,
       mark= between positions 0 and 1 step Step 
       with 
       beginscope[yscale=#1]
       pgfmathparseint(pgfdecoratedpathlength/28.45*100*Step)
       edefHightpgfmathresult
       ifnumpgfkeysvalueof/pgf/decoration/mark info/sequence number=1
       path (0,0)++(90: Hight/200 and Width) coordinate (b);
       fi
       ifnumpgfkeysvalueof/pgf/decoration/mark info/sequence number>1
       coordinate (b) at (d);
       fi
       path (b) arc (90:-135: Hight/200 and Width) coordinate (a);
       path (b) arc (90:-45: Hight/200 and Width) coordinate (c);
       path (b)++(Hight/100,0) coordinate (d);
       draw[fill,coilcolor!70!black]
       (c)
       .. controls +(-0.175,0) and +(-0.275,0) .. (d)
       .. controls +(-0.325,0) and +(-0.225,0) .. (c);
       draw[white,line width=2pt]
       (b)
       .. controls +(0.3,0) and +(0.2,0) .. (c);
       draw[fill,coilcolor]
       (b)
       .. controls +(0.275,0) and +(0.175,0) .. (c)
       .. controls +(0.225,0) and +(0.325,0) .. (b);
       endscope
       
       
       
      ]

      draw[Coil2=-1,CoilColor=red,Step=0.15] (0.5,0) -- ++ (0,-3);
      draw[Coil2=1.5,CoilColor=magenta] (1.5,0) -- ++ (0,-3);

      draw[Coil2=1,CoilColor=green!70!black,Step=0.02] (0,-4) 
       to [in=90,out=0] ++(2.5,-1)
       to [in=180,out=-90] ++(2.5,-1)
       to [in=-90,out=0] ++(2,1.5)
       to [in=-90,out=90] ++(0.5,3) arc (0:90:2);

      draw[Coil2=-1,CoilColor=green!50!cyan,Step=0.02] (0,-5) 
       to [in=90,out=0] ++(1.5,-1)
       to [in=180,out=-90] ++(4,-1)
       to [in=-90,out=0] ++(3,2.5)
       to [in=-90,out=90] ++(0.5,4.5) arc (0:90:2);

      draw[Coil2=1,CoilColor=cyan!30!blue,Step=0.05] (5.7,-2) arc (360:0:1.5);
      draw[Coil2=-1,CoilColor=cyan!70!blue,Step=0.05] (6.5,-2) arc (360:0:1.5);

      endtikzpicture
      enddocument





      share|improve this answer
























        up vote
        23
        down vote










        up vote
        23
        down vote









        If you put negative values for aspect and amplitude, you can get the mirrored coil, add this in the @marmot's answer may complete the desired output; also I added an option using markings to get some similar drawing that uses scope and yscale to invert the marking, then a new variable to control the coil color,when the path is straight it has good result, markings path lacks bending good results.



        EDIT: Added a control for marking step to improve bending results.



        RESULT:



        enter image description here



        MWE:



        documentclass[tikz,border=20pt]standalone
        usetikzlibrarydecorations.pathmorphing,decorations.markings

        begindocument

        begintikzpicture[
         CoilColor/.store in=coilcolor,CoilColor=black,
         Step/.store in=Step,Step=0.1,
         Coil/.style=
         double=black,
         draw=gray!50,
         decoration=
         #1,
         segment length=3mm,
         coil
         ,
         decorate,
         ,
         Coil2/.style=
         decorate,
         decoration=
         markings,
         mark= between positions 0 and 1 step Step
         with 
         beginscope[yscale=#1]
         draw[xshift=9.2,fill,coilcolor!70!black]
         (0,0)++(-135: 0.2 and 0.4) 
         .. controls +(-0.2,0) and +(-0.3,0) .. (90: 0.2 and 0.4)
         .. controls +(-0.33,0) and +(-0.23,0) .. (-135: 0.2 and 0.4); 
         draw[white,line width=2pt]
         (0,0)++(90: 0.2 and 0.4) 
         .. controls +(0.3,0) and +(0.2,0) .. (-45: 0.2 and 0.4);
         draw[fill=coilcolor,coilcolor]
         (0,0)++(90: 0.2 and 0.4) 
         .. controls +(0.3,0) and +(0.2,0) .. (-45: 0.2 and 0.4)
         .. controls +(0.25,0) and +(0.35,0) .. (90: 0.2 and 0.4);
         endscope 
         
         
         
        ]
        draw[Coil=aspect=-0.3,amplitude=-3mm,blue] (0,0) -- ++ (0,-3);
        draw[Coil=aspect=0.3,amplitude=3mm,red] (1.5,0) -- ++ (0,-3);
        draw[Coil=aspect=0.3,amplitude=3mm,green!50!black] (3,0) arc (90:0:3);
        draw[Coil=aspect=-0.3,amplitude=-3mm] (3,1) arc (90:0:4);

        draw[Coil2=-1,CoilColor=blue] (0,-4) -- ++ (0,-3);
        draw[Coil2=1,CoilColor=red] (1.5,-4) -- ++ (0,-3);
        draw[Coil2=-1,CoilColor=green!50!black,Step=0.065] (3,-4) arc (90:0:3);
        draw[Coil2=1,Step=0.048] (3,-3) arc (90:0:4);

        endtikzpicture
        enddocument


        UPDATE:
        Acording to @marmot's suggestion closing the gaps and drawing all the variations, using pgfdecoratedpathlength, /pgf/decoration/mark info/sequence number.



        RESULT:
        enter image description here



        MWE:



        documentclass[tikz,border=20pt]standalone
        usetikzlibrarydecorations.markings

        begindocument

        begintikzpicture[
         CoilColor/.store in=coilcolor,CoilColor=black,
         Step/.store in=Step,Step=0.1,
         Width/.store in=Width,Width=0.4,
         Coil2/.style=
         decorate,
         decoration=
         markings,
         mark= between positions 0 and 1 step Step 
         with 
         beginscope[yscale=#1]
         pgfmathparseint(pgfdecoratedpathlength/28.45*100*Step)
         edefHightpgfmathresult
         ifnumpgfkeysvalueof/pgf/decoration/mark info/sequence number=1
         path (0,0)++(90: Hight/200 and Width) coordinate (b);
         fi
         ifnumpgfkeysvalueof/pgf/decoration/mark info/sequence number>1
         coordinate (b) at (d);
         fi
         path (b) arc (90:-135: Hight/200 and Width) coordinate (a);
         path (b) arc (90:-45: Hight/200 and Width) coordinate (c);
         path (b)++(Hight/100,0) coordinate (d);
         draw[fill,coilcolor!70!black]
         (c)
         .. controls +(-0.175,0) and +(-0.275,0) .. (d)
         .. controls +(-0.325,0) and +(-0.225,0) .. (c);
         draw[white,line width=2pt]
         (b)
         .. controls +(0.3,0) and +(0.2,0) .. (c);
         draw[fill,coilcolor]
         (b)
         .. controls +(0.275,0) and +(0.175,0) .. (c)
         .. controls +(0.225,0) and +(0.325,0) .. (b);
         endscope
         
         
         
        ]

        draw[Coil2=-1,CoilColor=red,Step=0.15] (0.5,0) -- ++ (0,-3);
        draw[Coil2=1.5,CoilColor=magenta] (1.5,0) -- ++ (0,-3);

        draw[Coil2=1,CoilColor=green!70!black,Step=0.02] (0,-4) 
         to [in=90,out=0] ++(2.5,-1)
         to [in=180,out=-90] ++(2.5,-1)
         to [in=-90,out=0] ++(2,1.5)
         to [in=-90,out=90] ++(0.5,3) arc (0:90:2);

        draw[Coil2=-1,CoilColor=green!50!cyan,Step=0.02] (0,-5) 
         to [in=90,out=0] ++(1.5,-1)
         to [in=180,out=-90] ++(4,-1)
         to [in=-90,out=0] ++(3,2.5)
         to [in=-90,out=90] ++(0.5,4.5) arc (0:90:2);

        draw[Coil2=1,CoilColor=cyan!30!blue,Step=0.05] (5.7,-2) arc (360:0:1.5);
        draw[Coil2=-1,CoilColor=cyan!70!blue,Step=0.05] (6.5,-2) arc (360:0:1.5);

        endtikzpicture
        enddocument





        share|improve this answer














        If you put negative values for aspect and amplitude, you can get the mirrored coil, add this in the @marmot's answer may complete the desired output; also I added an option using markings to get some similar drawing that uses scope and yscale to invert the marking, then a new variable to control the coil color,when the path is straight it has good result, markings path lacks bending good results.



        EDIT: Added a control for marking step to improve bending results.



        RESULT:



        enter image description here



        MWE:



        documentclass[tikz,border=20pt]standalone
        usetikzlibrarydecorations.pathmorphing,decorations.markings

        begindocument

        begintikzpicture[
         CoilColor/.store in=coilcolor,CoilColor=black,
         Step/.store in=Step,Step=0.1,
         Coil/.style=
         double=black,
         draw=gray!50,
         decoration=
         #1,
         segment length=3mm,
         coil
         ,
         decorate,
         ,
         Coil2/.style=
         decorate,
         decoration=
         markings,
         mark= between positions 0 and 1 step Step
         with 
         beginscope[yscale=#1]
         draw[xshift=9.2,fill,coilcolor!70!black]
         (0,0)++(-135: 0.2 and 0.4) 
         .. controls +(-0.2,0) and +(-0.3,0) .. (90: 0.2 and 0.4)
         .. controls +(-0.33,0) and +(-0.23,0) .. (-135: 0.2 and 0.4); 
         draw[white,line width=2pt]
         (0,0)++(90: 0.2 and 0.4) 
         .. controls +(0.3,0) and +(0.2,0) .. (-45: 0.2 and 0.4);
         draw[fill=coilcolor,coilcolor]
         (0,0)++(90: 0.2 and 0.4) 
         .. controls +(0.3,0) and +(0.2,0) .. (-45: 0.2 and 0.4)
         .. controls +(0.25,0) and +(0.35,0) .. (90: 0.2 and 0.4);
         endscope 
         
         
         
        ]
        draw[Coil=aspect=-0.3,amplitude=-3mm,blue] (0,0) -- ++ (0,-3);
        draw[Coil=aspect=0.3,amplitude=3mm,red] (1.5,0) -- ++ (0,-3);
        draw[Coil=aspect=0.3,amplitude=3mm,green!50!black] (3,0) arc (90:0:3);
        draw[Coil=aspect=-0.3,amplitude=-3mm] (3,1) arc (90:0:4);

        draw[Coil2=-1,CoilColor=blue] (0,-4) -- ++ (0,-3);
        draw[Coil2=1,CoilColor=red] (1.5,-4) -- ++ (0,-3);
        draw[Coil2=-1,CoilColor=green!50!black,Step=0.065] (3,-4) arc (90:0:3);
        draw[Coil2=1,Step=0.048] (3,-3) arc (90:0:4);

        endtikzpicture
        enddocument


        UPDATE:
        Acording to @marmot's suggestion closing the gaps and drawing all the variations, using pgfdecoratedpathlength, /pgf/decoration/mark info/sequence number.



        RESULT:
        enter image description here



        MWE:



        documentclass[tikz,border=20pt]standalone
        usetikzlibrarydecorations.markings

        begindocument

        begintikzpicture[
         CoilColor/.store in=coilcolor,CoilColor=black,
         Step/.store in=Step,Step=0.1,
         Width/.store in=Width,Width=0.4,
         Coil2/.style=
         decorate,
         decoration=
         markings,
         mark= between positions 0 and 1 step Step 
         with 
         beginscope[yscale=#1]
         pgfmathparseint(pgfdecoratedpathlength/28.45*100*Step)
         edefHightpgfmathresult
         ifnumpgfkeysvalueof/pgf/decoration/mark info/sequence number=1
         path (0,0)++(90: Hight/200 and Width) coordinate (b);
         fi
         ifnumpgfkeysvalueof/pgf/decoration/mark info/sequence number>1
         coordinate (b) at (d);
         fi
         path (b) arc (90:-135: Hight/200 and Width) coordinate (a);
         path (b) arc (90:-45: Hight/200 and Width) coordinate (c);
         path (b)++(Hight/100,0) coordinate (d);
         draw[fill,coilcolor!70!black]
         (c)
         .. controls +(-0.175,0) and +(-0.275,0) .. (d)
         .. controls +(-0.325,0) and +(-0.225,0) .. (c);
         draw[white,line width=2pt]
         (b)
         .. controls +(0.3,0) and +(0.2,0) .. (c);
         draw[fill,coilcolor]
         (b)
         .. controls +(0.275,0) and +(0.175,0) .. (c)
         .. controls +(0.225,0) and +(0.325,0) .. (b);
         endscope
         
         
         
        ]

        draw[Coil2=-1,CoilColor=red,Step=0.15] (0.5,0) -- ++ (0,-3);
        draw[Coil2=1.5,CoilColor=magenta] (1.5,0) -- ++ (0,-3);

        draw[Coil2=1,CoilColor=green!70!black,Step=0.02] (0,-4) 
         to [in=90,out=0] ++(2.5,-1)
         to [in=180,out=-90] ++(2.5,-1)
         to [in=-90,out=0] ++(2,1.5)
         to [in=-90,out=90] ++(0.5,3) arc (0:90:2);

        draw[Coil2=-1,CoilColor=green!50!cyan,Step=0.02] (0,-5) 
         to [in=90,out=0] ++(1.5,-1)
         to [in=180,out=-90] ++(4,-1)
         to [in=-90,out=0] ++(3,2.5)
         to [in=-90,out=90] ++(0.5,4.5) arc (0:90:2);

        draw[Coil2=1,CoilColor=cyan!30!blue,Step=0.05] (5.7,-2) arc (360:0:1.5);
        draw[Coil2=-1,CoilColor=cyan!70!blue,Step=0.05] (6.5,-2) arc (360:0:1.5);

        endtikzpicture
        enddocument






        share|improve this answer














        share|improve this answer



        share|improve this answer








        edited Sep 7 at 4:09

























        answered Sep 6 at 17:53









        J Leon V.

        6,775528




        6,775528



























             

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