I’m very happy to see that visibility tracks are supported in V-Ray 5 GPU. I’m hoping for a couple things further:
- that shadows cast by objects that are only partially visible could also respect the visibility value. Right now the shadows ‘pop’ in at 100% while the object is fading in nicely.
- that objects with multi-sub object materials would also respect visibility values. Right now they are always visible as far as I can figure.
I think you may be much better off with this method Fade an object, like on photoshop not the effect of animating the visibillity channel - General - Chaos Forum
Far more control and no need to go near the horrible visibility channels 
It is however bugged a little, which I’ll post about tomorrow…they’ll fix it quickly I’m sure - for the most part it works
Thanks for the idea. I might give that a go just so I understand it better as an option, but I have a LOT of objects to deal with and I think I’d generally prefer managing visibility tracks to multiple materials.