Curves (outline) from an alpha sequence

[neofytos]

Hello,
Is there a way to have silhouette curves(animated) extracted from an alpha sequence, I know cinema 4d can do that with the Vectorizer. Is there a trick, plugin, script, that can do that in Maya?

Thanks
N.

[joojaa]

Depends on what you need. can think of 8 different scenarios.

To take a arbitreary anc contrived example here:

http://www.creativecrash.com/forums/mental-ray/topics/extruding-an-object-via-a-shader---2

[neofytos]

Thanks Joojaa,
 That network looks very advanced for me but I will give it a shot.
At the end of the other post you said something about importing a sequence of vector drawings in maya, can this be done?

[joojaa]

Yes offcourse.

 A computer application that can not repeat a sequence of proceedings is not much a of a computer program. But alas its a definition question all programs can do this by definition.

[neofytos]

Well all sound good in theory, I have no idea how to do that shading network, I don't even know from where to start, If you don't mind can you please post some more details about that shader?

[joojaa]

Well i would have assumed the picture description is pretty self explanatory, with the added question of what the surface sampler is doing. But I digress. Heres a script snipet that builds it for you. Be sure to use mentalray, fine view dependnt displacement approximation with a 0.5 -1 length and sufficently accurate alpha.

proc string[] createShader(string $type){
  string $shader = `shadingNode -asShader $type`;
  string $set = `sets -renderable true -noSurfaceShader true 
                    -empty -name ($shader + "SG")`;
  connectAttr -f ($shader + ".outColor") ($set + ".surfaceShader");
  return {$shader,$set};
}
 
{
  string $shader[] = `createShader lambert`;
  string $plane[] = `nurbsPlane -p 0 0 0 
                                -ax 0 1 0 -w 1 
                                -lr 1 -d 3 -u 1 
                                -v 1 -ch 1`;
  sets -e -forceElement $shader[1] $plane[0];
 
  string $file = `shadingNode -asTexture file`;
  string $disp = `shadingNode -asShader displacementShader`;
  connectAttr -f ($file + ".outAlpha") ($disp + ".displacement");
  connectAttr -f ($disp + ".displacement") ($shader[1] + ".displacementShader");
 
  string $info = `shadingNode -asUtility samplerInfo`;
  string $cond = `shadingNode -asUtility condition`;
  connectAttr -f ($cond + ".outColor") ($shader[0] + ".transparency");
  connectAttr -f ($info + ".pointObjY") ($cond + ".firstTerm");
  setAttr ($cond + ".operation") 2;
  setAttr ($cond + ".secondTerm") 0.001;
}

PS you can project the carton substructure from the side

 

[neofytos]

Thank you very much Joojaa. You are really good, I will give it a try but for me these type of stuff is nuclear science I shouldn't commit to this project its way too advanced for my knowledge.
Thanks again for your time and help.