Refraction Problem

Hello,

After I installed 1.7, I encountered something new.

I have a frosted glass behind (refraction level 0,9 glossiness 0,2)

I have an another glass at foreground (all glass models are mesh btw, not planes)
If I use a glass material with thin(no refraction) selected I get a correct result.
If I use a glass material without selecting thin(no refraction) I get a messy result.

Correct me If I miss anything, but I think this is a bug.

It is a bug. Could you send us a scene where this is happening - Chaos

It should go away if you:
-increase uhd cache precision to ~4
-change uhd cache preset from still image to animation
-switch to path tracing only (pt+pt in performance tab)

I can’t send the scene unfortunately (confidentiality issues),
I’ll try to recreate the problem in a new scene.

That would be great, thanks a lot!

I’m having trouble to recreate the problem in a new scene. working on it though.

besides, it even varies in the same scene, same camera. could be based on model itself (imported .skp)

Model could be a problem, for example if there are coplanar or otherwise intersecting faces.
Have you tried the hints from my previous message?

glasses literally floating in the air right now (not touching anything), I still get stains.

I tried your hints, stains got smaller but they’re still exists.

I am afraid we will need a scene then. Or at least some hint how to reproduce it. What is the material setup? What lights are used? …