Grainy reflections in Vray 3.20

[Fëanor]

Hi everyone!

I've just upgraded to vray 3.20, and I'm having this weird problem. This is a crop of a final render where you can see the grainy reflection:

 

 

As you can see, the top of the folder looks all wrong. I tried increasing the reflection subdivs, but I had no luck.

The weird thing is that the problem disappears when I do a region render:

 

 

This is my first time starting a scene from scratch in Vray 3.20. I never had this problem using the same materials in vray 2.4, so that's why I think that maybe this has something to do with one of the new vray render options?

 

I'm using Irradiance map and Light cache.

 

Thanks a lot and excuse my broken english.

[timothyhanson]

Since the release of Vray 3 you really don't need to use light caching hacks anymore. Go brute force / brute force for everything because it is fast enough to handle it. Not only will you never have flickering in your animations, but it is a smoother render. Give that a try, and also look into clamping max ray intensity to 20 in your global advanced options.