Cloth tear geometry and shading detail


Cloth tear geometry and shading detail




Been adding geo detail to the torn cloth and shading the additional geo. Shading sure is fun! :)

Thickness added to the cloth geo
Extrude sides are extruded out again

The second extrusion is done twice, once for the U direction, and once for the V direction. Polyframe is used to get the UV gradient to extrude along, vopsops are used to move the extrudeFront points after extrusion as you can’t control the extrusion per point with just a polyExtrude node…

The extrusion is done twice so that the two different surfaces represent the opposing thread directions. since my geometry (and therefore tears) are in line with the U and V direction, the effect is not obvious in this case.
The extra geo after shading

The .hip file below has a slightly newer shader than in the video and the image above, I removed the part of the shader that created the soft ramp for the alpha edge and used just the thread noise instead; it now looks more like:

Slightly newer shader than what is seen in the video, click for big

The UV space can be transformed after the sim to change the thread direction, the following has the UV space rotated 90º, you can see threads running in two directions on a single edge:

Rotated UV space
There are a few issues with this … the first is that the geo that is added after the sim penetrates the main geo. The extra edge could be added in the SOP Solver so that they collide properly, maybe something for the future!
Also there is a part in the shader that adds creases to the normal, this is causing some wacky normals … anyway, here is the video:



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