Vray Break SSS into Render Passes

[Ruchit]

Hello, i m new to Vray for maya and i want to know how can i Break SSS into Render Passes (i.e Diffuse, Front Scatter, Back Scatter, etc separately).

Here is tutorial for How to render SSS Separately using Mental Ray
www.youtube.com/watch?v=SylbV-S98Hc

[Svetlozar Draganov]

Currently it is not possible to break VraySSS material to separate components like Front and Back Scatter.
It is possible however to extract Diffuse, Lighting, Reflection and etc components, just add these Render Elements in the list and V-Ray will export them.

[Ruchit]

For Alternative Solution i tried
=>Take 3 SSS Shader for (Shallow, Medium & Deep)
=>One for Shallow(In this Medium & Deep Will be black)
=>One for Medium(In this Shallow & Deep Will be black)
=>One for Deep(In this Medium & Shallow Will be black)
=>Render this 3 different shader using material select

Here is test render




But Problem with this is VFB is showing proper but without VFB (Turn Off) i m not able to save output. And tell me is this right way to do ?

[Svetlozar Draganov]

Vray Render Elements cannot be exported from Maya Frame Buffer - you have to use Image File Output for that purpose:


I am not sure whether the result from the combined separate shaders will match the result from single SSS material.
Are you rendering a separate pass for each shader or you are using VrayBlendMtl with 3SSS shaders assigned?

[Svetlozar Draganov]

Ok I've just run a quick test with VrayBlendMtl containing three separate Skin Shaders.
Each Skin shader has only one component activated - Shallow , Medium or Deep.

The result as I suspected is not the same as single Skin material with all components active but it is definitely a good workaround to get what you are looking for since the composition of the separate Skin-materials is equal to the SSS-render element, which means that you can control the separate components of Skin material in Nuke.

[Ruchit]

I was doing all separately (without using VrayBlendMtl), three material select render element for three SSS shader.
Yeah you are right about result, output from single shader is different & from multi-shader is different.

I request you to add this functionality in next version. Add to wish list

Thank you

[Svetlozar Draganov]

We've added a new feature request about that into our system.
We'll let you know when we have some news on that regard.