Glass refraction weird circles

Hi guys,

I have an issue with my glass window that create some weird effects in Vray. I tried a few different material, try take away the thickness of the window, different light settings, but this weird effect remains. I’m sure there’s an explanation and something to do about it, I’m just not able to find it.

Could maybe someone explain this one to me?

Thanks a lot!


Are you able to upload your model or at least the part with the glass for a closer look?


I tried two different surfaces, so there’s the actual window hidden in this save.

EDIT: Saw on another forum a possible solution, seemed to work, I changed the IOR of the material to 1.1 and the circles are gone.

EDIT2: And now it reappeared. I don’t know what I did but it’s back!

I’m not sure exactly why you’ve set up your window/background image the way you have it. It looks like this is a ‘Z-Fighting’ issue where you have two planes sharing the same surface.

Try deleting that black surface. Or better yet, punch a hole in your wall and move your background image away from your house model.

Seems to render ok now. FYI I have V-Ray 4 installed so the lights and other render settings aren’t showing since I assume you’re using version 5?

I found that the issue of the glass weird effect was coming from the thickness of the object. So I replace the window by a single surface. It works now. Though I need to find the right setting for the reflection.