I'm trying to create a render where I have an invisible object blocking parts of another visible object. Think of an invisible cube with a person standing in back of it. Where the cube is in front of the person, that part of the person doesn't render, but the areas of the person not blocked by the cube do render. This is for replacing the cube in another program.

I know one way to do this is to make the cube a bright green or something and then key that out in the other program, but is there an easier way to do this blocking natively without having to key it out? Making the cube invisible but still covering up objects behind?

I'm in PPro 2012 BTW, and I'm doing an animation and putting it in After Effects.

The only way I know is to use chroma-key. Depending on what you are doing just overlay the thing and dont try to fit it into a chroma-key area.

That's what I'm doing but I was hoping Poser has some built in way to avoid this extra step of keying and the artifacts that happen when not getting a nice clean key. I guess I'll pobably have to jump to another 3D program to avoid this :(

if cube opaque but not visible to camera (PP2012 or later), perhaps that would provide a mask.  no, wait, just tried it, doesn't work.  other option is high refractive index.  no, that don't work either.  third option is render with cube dead-black, with no lite interactions, to give clean mask.

If the camera and the cube don't move there is a way of "projection mapping" the background image onto the cube

http://www.renderosity.com/mod/forumpro/showthread.php?message_id=3410629&ebot_calc_page#message_3410675

DurrenUK, Thanks! that should do it!

Darren,

It worked fantastic! Thanks a million!