Matte / holdout shader

john_babec29f

I generally render in layers, then composite everything together after.  I'm kind of new to Daz3d - in Maya / Mental Ray / Renderman I would create a black hole shader, one that generates no color whatsoever in scene, but does occlude objects and cast shadows.  Is there a way to do this in Daz3d?

 

thanks!

mjc1016

For which renderer?

 

Tobor

If for Iray, do a search in the forum for Iray Matte Objects. There's a script you can apply to the object that will do (from the sound of your request) what you want.

For compositing, you can also render as nodes using the Canvas feature. You can render individual elements by selecting them, and then combine as you wish. Something like this (it's the opposite of a matte object, but is also useful for comping):

 

mjc1016

Save you some trouble searching...

https://www.daz3d.com/forums/discussion/56978/shadowcatch-surface-iray

Tobor

Yes, that's a pretty good thread, though it doesn't show many examples of using the feature holdback mattes. The important points are applying and activating the matte, and lighting. Remember that shaders used on the objects matter, and influence the end result, as does types of lighting.

Here is a simple example showing a matte cutout of a sphere. Note that the matte does not produce a transparency in the HDRi background. I've added a simple colored plane to demonstrate the principle.

 

Tobor

Duplicate posting