Rendering & Masking

[Raptisoft]

This thread is specific toward some of the higher end 3D programs out there. I am using 3DSMax, but a solution in another package might give me a keyword that I can google to find the solution. Probably the process I'm trying to do here has some weird buzzword attached to it, just to make people have to go to college to do it.

Okay, in 3DSMax, I'm rendering a worm thing oozing out of a tube. In my final render, I want the worm thing to show up, be occluded by the tube, but NOT render the tube itself. So essentially, the tube becomes a mask that has the worm thing cut out in 3D space, and this way I can have the worm come out of in-game geometry.

Does anyone know how to do this? How do you set up a material to render RGB and Z, but not alpha? I can render the tube in the same color as the background, and it would be fine, except that it shows up in the alpha layer anyway.

Thanks in advance for any help you can give.

[Reactor]

That isn't hard to do in XSI and Maya, mainly because you have good control over how shaders are connected to the rendering pipeline, but 3dsMax I'm not sure. You might want to mention what version you're using...

If no one here is able to help, try here-

http://www.cgtalk.com/forumdisplay.php?f=6

[Wayward]

In 3DSMax, one way is to apply a 'Matte/Shadow' material to the occluding object. Be sure to turn off 'Receive Shadows' on the material.

[Raptisoft]

Ah, thank you. The magical secret word was "matte."

Thanks a lot!