Geometry paintable SSS

[digitalx3d]

Just a thought. I was inspired when I looked at my cat this morning and noticed the SSS in his ears.

Would it be possible to paint SSS areas, sort of like vertex paints? Example: You have a mesh of a cat. You apply a "SSSpaint" modifier to the object, and paint the ears of the cat. This way the renderer knows that it only needs to compute SSS for the painted areas, and not the entire cat!

Or is there another way to control this already?

John Pruden
Digital-X

[Basse]

You can always use the multisub material and have a separate material just for the ears by using the material ID.

[RErender]

This can also be achieved by placing a mask in the translucency map slot

[trixian]

Or....Just paint the vertices you want with the vertex paint modifier and use the vetex paint map instead of the mask map.

[digitalx3d]

trixian,
Don't know why I didn't think of that!!

John P.

[trixian]

Actually, I only mentioned it because it was directly relevant to your original question. Personally I would go with the blend material with a bitmap\map approach for better flexibility and precise controll.
Not sure if this then makes the whole model slightly more cpu intensive, but in that case, one could make a instanced mat tree, where only the faces you need sss on have an uniqe id, and a blend material assigned, while the rest of the model has the basic non-translucent material.
Could be more hassle to set up time wise than just going for the single material approach though.

[vlado]

A single material is going to be much faster since VRay will not compute sss at all for black areas of the sss map. If you use a Blend material, you will force VRay to compute the sss effect everywhere, even if it's not visible in the end.

Best regards,
Vlado

[trixian]

Nice...Good to know. I'll try to avoid blends and multi-subs as often as I can in the future

[Basse]

A single material is going to be much faster since VRay will not compute sss at all for black areas of the sss map. If you use a Blend material, you will force VRay to compute the sss effect everywhere, even if it's not visible in the end.

Best regards,
Vlado

Will Mulit Sub materials compute as Blend of Single material?

[vlado]

Will Mulit Sub materials compute as Blend of Single material?

They will render with the speed of single materials.

Best regards,
Vlado