Hi - I'm trying to render some water on an opaque bottle. I have the live-action plate of the bottle projected as a texture onto the bottle geometrry. The bottle's render tab has “phantom” checked. So, that works great - the water refracts the bottle, as it is in the live action plate.

But, when the water goes behind the bottle, it is not matted out correctly. What is the simplest way to get my water to refract and reflect the bottle, and also respect the bottle as a hold-out object?

thanks

Hi,

Welcome to Houdini-land. To do what you want, please make sure to turn off “Phantom” and “Matte shading” on the bottle and go to the Mantra ROP's Objects tab and put the bottle into the “Forced Matte” parameter.

This will make the bottle a matte and phantom object at the same time. I've attached an example hip file.

Cheers!
steven

Oh Em Gee! That totally worked! Thank you, thank you, thank you.

OK - Bonus question: Now the bottle shows up in the AOV's. Is there another check box somehwere I can hit to remove the bottle from the depth pass, the normals pass, etc.?