Am I correct that V-Ray Next GPU is not compatible with Visibility Tracks having a value other than 1 and 0? I can’t find any reference to Visibility Tracks in the documentation.
Digging in a little further, I realize GPU does support visibility tracks… BUT… it does not support Multi-sub materials with visibility tracks. Anything non-zero (between 0-1) is fully visible. I’d love to hear from someone at Chaosgroup about this and any possible work-around!
One other bothersome thing… when using a standard material to get the visibility to come in and out properly, the shadow cast by that object is either *on* or *off*. So, even though the object is fading in nicely, the shadow pops in immediately.
That’s a known one, but it’s not very trivial to fix. As a workaround you can use different opacity map for each material.
Thanks for the response. I have hundreds of objects each fading in at different times - I can’t see OP maps working. I’m sticking to CPU for this one 
My goal lately has been to use GPU for everything I can, hoping to move that way completely. Running into brick walls like this is a bit frustrating to that end. Not being a programmer, I can’t relate to why this might be difficult to do, but I believe you when you say it is 
I hope though that it can be done as this seems like a fundamental functionality to me! Thanks for all the good work you folks do :-)