How to project textures from a geometry onto another geometry?

Hi,

Imagine the following scenario:
I have Object A in front of Object B. Now I want to hide A for primary rays and just project the shaded texture of A onto B through camera projection. How would I go about that? It’s basically screen mapping but nut based on a texture alone but based on a texture already on an object.
Basically I want to cast rays through A onto B and shade the respective point on B with the shading result of A (more specifically maybe only the diffuse shading component).

This maybeto simple for what your after but could you not just render object A from the main camera with only the shading info you require. And the project that information/render back onto B via standard Camera Mapping?

Agree with above, either the camera map modifier, or if it’s a particularly tricky shape that can’t be camera mapped you might look into the projection modifier. I haven’t had much need to ever use it but from my understanding that’s along the lines of what you described, you’d just use it for diffuse instead of usual normal map use.