Clip Geo not rendering under Object Mask?

[shawn]

There seems to be an issue where Clip Geo geometry doesn't properly cut out objects when it's nested under a null with a Object Mask AOV applied.

The two hierarchies in this render are the same, but in the one on the right the cloner object with Clip Geo is parented to a null with a Custom Mask AOV applied (along with the other objects in that hierarchy). In the correct render on the left the hierarchy does NOT have an Object Mask AOV applied.

Is this the normal behavior for Clip Geo? If so I guess I'll have to use a constraint tag to parent the Clip Geo object to the main hierarchy (when I want a matte generated for that group) without having it actually in the group.

Cheers.

Shawn Marshall

ClipGeo-AOV_Bug.c4d.zip

[peter.horvath6V6K3]

There's a current limitation, that clip_geo must be the root shader in a network. When adding an object mask, it actually adds an aov_write shader after the clip_geo as a new root. You should see a warning in the log.

What are you after exactly? Do you want to see the mask of the clipping pieces in the AOV? I guess not, right, only the final clipped geo. So you need to move the object with the clip_geo shader outside of the hierarchy which has the object mask tag applied.

Maybe the plugin could do this automatically and do not apply the mask for clip_geo shaders.

[shawn]

Thanks for the reply, Peter. I basically just want my object to render correctly with the cutouts and have a correct matte so I can isolate the object for compositing. It looks like I've come up with the correct structure to do this, so I should be good to go.

Perhaps the manual could include a prominent alert on the Clip Geo page that warns the user against having the Clip Geo object parented to an object with a Custom Mask AOV.

Cheers.

Shawn

[peter.horvath6V6K3]

Next release will have a 'fix' to skip the object masks on clip_geo shaders.

[peter.horvath6V6K3]

clip_geo is now automatically skipped when under an Object Mask tag in C4DtoA 3.1.0.2. Your original setup should work fine in this version.