Is there any way to animate an object's opacity through it's material in VRay?

[Jim S]

I can't seem to be able to animate an object's opacity in VRay by using materials. I tried using a color map in the object's opacity map slot, as well as in the refraction slot, with an IOR of 1, and while I can get an object to be invisible for a frame, I can't seem to find a way to have a smooth animation from fully opaque to fully transparent over time.

I need this to work with materials, and not through an object's visibility track.

I already looked at this post:https://forums.chaosgroup.com/forum/...aren-t-working ...and that leaves me to believe that animating an object's opacity in VRay is impossible.

Why is this?! I can easily do this with standard materials when rendering with scanline, so why is VRay incapable of doing this? There are some specific render effects that I'd like to do for an animation that involve animated opacity, but I don't know how to achieve this with VRay.

Someone please explain if there is a way to do this.

Developers - please work on this for future releases!

It is very frustrating that I can't animate opacity in VRay!!

[fixeighted]

You can try the method explained here https://forums.chaosgroup.com/forum/...illity-channel

[Jim S]

Hey fixeighted, thanks for your help! I tried messing with the example file, and I can confirm that an animated version of that setup works.

I still wish that for VRay animating the opacity or refraction map in the material would work in a more straightforward and less convoluted way so as to be more user friendly and intuitive.

[^Lele^]

You can animate opacity animating the map's output value, f.e., just like one would animate any other map-based channel in a shader.
If the map doesn't have an output section (f.e., some procedurals), it's just enough to put it as child of an output map.
(see attached.)

I'm not sure how it should be made simpler: do you have suggestions?

[fixeighted]

Nice one Lele...should update that other post, as this is a much simpler method

[Jim S]

Lele, thank you very much for your input. I went and tried your approach, and I also tried an animated color map in the material's opacity slot, and both approaches work fine. So I apologize for any confusion.

I swear I had done a test with this maybe a year or two ago, and an animated opacity map would cause the object to suddenly pop into place, rather than fading in smoothly. Sorry for assuming that I was still dealing with the same issue, since an animated map clearly works OK now.

However, I am still dealing with some weird opacity issues which are specific to my scene, and I solved some of them by playing with the render settings, but some issues still remain.

These issues have to deal with multiple overlapping transparent objects. I am trying to render an array of cloned cubes (100x100x100) and I was initially getting a weird black box when the material was at 0% opacity, but I realized that the main render setting that affects this is the Transp Max Levels in the Global Switches tab. I tried to increase this number by a lot, and that helped to make the objects completely transparent, but a weird shadow on the ground remains.

Any thoughts on how to fix this?

[Jim S]

Example file attached

[fixeighted]

That is likely to be because the cube is coplanar to the ground, so just move it up a tiny bit and it'll disappear.