How to render object always on top/in front of another object?

[zbugni]

Hey everyone, basically what I have is this:

and what I want is this:

Obviously, it looks like I could just move the pig head up in space haha. But I have a more specific case that requires the pig head to be visible through the plane giving the ILLUSION that it's on top of it. Put simply, I want the pig head to always be drawn/rendered on top of the plane, regardless of depth/occlusion.

It's really easy to achieve this with compositing, but I'm hoping to pull this off at render time using materials in Mantra. I'm open to some complicated node setups (maybe turning the plane transparent wherever the pig head is behind it???) But hopefully it's just an easy setting that I've missed. Thanks so much in advance!

[Librarian]

@zbugni hm..maybe to use trick with bbox in for-loop and somehow export CAM-coordinates in mat Shop ..but how ????? hm

 

trick.hiplc

[zbugni]

15 hours ago, Librarian said:

@zbugni hm..maybe to use trick with bbox in for-loop and somehow export CAM-coordinates in mat Shop ..but how ????? hm

This is an awesome setup that gets me inspired! But yeah, I have no idea how to get the result I want in a shading context. I don't actually want to move the pig head physically. I just want it to always be visible, even if it's behind an object in space.

[TobyGaines]

sounds like more trouble 'plus' less flexibility than just comping it