Using Forced Matte in Object List to Matte Vray VolumeGrid producing wrong alphas

[frame48]

There seems to be problems using Force Matte to matte the Volume with the rest of the objects in the scene. Attaching alpha images of the beauty render, and the Volume element over the Environment element. I cant tell if its a velocity issue or an issue with the Volume intersecting some objects. Can't provide a scene unfortunately.

[Gosho.Genchev]

Hey frame48 ,

I'm not sure that I'm 100% clear on this - are you attempting to put the Geometry node holding the volumes in the Forced Matte list? If so, this will not work as we currently do not support Matte Properties over Volumetrics. It's high on our priority list of features for future releases.
As a possible solution, may I suggest using Cryptomatte for generating masks in Comp?

Best regards!