I have been doing my own R&D with layered materials.
Sometimes when I get stuck in VRay I will try RenderMan because its a completely differed rendering package.
One thing I noticed that Renderman does really nice is layering materials and their bump maps. By default, there is a strong sense of distinction between the layered bump maps in RenderMan. I have an example scene but maybe its easier to just link you to this video I found. It is also a great illustration of what I mean.
You can see about 6 min into the clip, the artist creates the layered bump materials.
Each substance appears distinct from each other by default, whereas in V-Ray the artist needs to use the VRayBumpMtl.
Notice how the paint appears to be lifed from the rust and the rust appeasr to be eroding the surface? There is a noticable lip on the paint without the need for a VRayBump material operation.
Can we VRay user please have this kind of behaviour? so we don’t need the VRayBumpMtl?
Thank you again Chaos Group, for all your great work!
Well, why do you not try layer the bumps *before* adding them to a shader?
I do not see what the bumpMtl would be used for here, it’d just complicate matters, and depart from what’s shown in the Pixar tutorial: the blend two shaders with two different bumps, not use a bump shader at the top.
See attached example (two shaders, each with their bump, one mask in a blend.).
scene is max 2017.
It’s pretty much identical to the pxr tutorial, which is nothing new (to us, which had the *blendMlt* for a decade and a bit. It’s new to them, though.).
In plain English, you simply blend two separate shaders, each with their full characteristics (including bump), through a mask. bumps.zip (69.5 KB)
Lele, Thank you so much for your time and for responding. Thank you for the sample scene.
I have to put forward to you and to chaos group that I believe the Renderman workflow is objectively easier for users.
You just plug your maps into the bump of each material, then connect each material into a blend material. Then use a pattern to act as a mask. The bump adds a ‘lip’ automatically.
Thank you again Lele for the demonstration file. I will follow that workflow you set but I think Renderman is more user friendly in this very specific case.
