How can i render Object Masks for Procedural Objects?

[Anonymous]

When an Object Mask Tag is added to an Arnold Procedural, the object mask aov does not create any result. It seems as if it is a problem for the Object mask to work on an external file/object that is not in the scene?

[peter.horvath6V6K3 · Accepted solution]

It's a limitation, object mask can not be used with a procedural.

Object mask is actually an aov_write_float shader added to the root of the shading tree, thus it would require to modify the shader network inside the procedural, which is rather complicated.

[Anonymous]

Thanks for the clarification, Peter!

[peter.fagerberg]

Any creative ideas on the best work-around for this? Cryomattes seem to work with procedurals so that's one way to go, but it's a lot of manual work if you just want a mask in Photoshop... Is there a better way mayhaps?