I keep forgetting which to use for proper render mattes for Vray. There are 4,
Multimatte is the best
- Material Select
Material Select, you drag the material and plug it into the material select element. Named after the material. It only renders the material without anything else.
- Render ID
During render time, all objects get assigned an ID. So when using this...it automatically colours each other. No aliasing and the colors are random. Not the best use.
- Material ID
One has to go to the hypershade and assign the Color ID or Material ID to the shader. Ideally, only use RED, GREEN & BLUE as when using the color selector the color can mix up. To solve this, there is the multimap.
Under the shaders color ID there is a material ID. Assign each material a number.
For objects, use apple single object property to selection and then assign an ID number to that object.