Long time, no post - been out of the CG side of things for a while!
The studio I work at is in the process of moving over to Maya for a new TV show, and I'm getting our rendering/comping pipeline ready. Obviously we want to render out our CG in multiple passes for finer control during compositing. I'm looking at using EXR files to store multiple passes out of Maya (currently 2009, but will be the latest version soon). That's fine, as long as all my passes are in one render layer, but what if I have multiple layers, each with material/render overrides?
For example, I've created a custom surface shader that gives me fine control over depth map rendering. I've created a new render layer (called depthMapCJL), added in my geometry and overridden the shader with my custom shader.
In my masterLayer I've got a series of render passes, such as diffuse, ambient, AO, reflection, refraction, normalMap, specular.
This is all fine - I can render everything, but the masterLayer and depthMapCJL layers both render out as separate EXR files. Is there any way I can add the output from depthMapCJL to the EXR file rendered from the masterLayer?
I've tried using Associated Pass Contribution Maps. I've also tried creating a new pass called "customDepthCJL" in my depthMapCJL layer, and adding that into my Associated Passes in masterLayer, but it seems the master layer just renders it with its own materials, not the overridden ones from my depthMapCJL layer!
Another example might be adding a second specular pass, made using a different material, e.g. with a bump map, that wouldn't be part of the masterLayer's materials.
Is it possible to render multiple render layers into one EXR file directly from Maya/mentalray, or do I need to render out multiple file sequences for each layer? Any help here would be appreciated!