Glass Refraction Problem

I’ve been tweaking my glass settings for a recent project and have discovered a refraction problem. Basically, objects close to the glass are causing black refraction spots on my glass. As I remove those objects, the problem starts to go away. Been tweaking my settings but can’t fix the issue.

Reflections have been completely turned off to narrow down the problem.

Would love some thoughts:




Okay, just found that if I turn my fog multiplier to zero the problem goes away, but I’m left with no fog. lol.

EDIT. actually, the problem remains when camera is at a different angle.

Boo.

Well, I found a quasi fix. The original glass panes were made from a standard Max box - which I’ve never had an issue with in the past. I recreated them as planes, but with the ‘shell’ modifier applied, and the problem went away. Bizarre.

It’s strange indeed. If you still have the old scene around, can you send it to me at vlado@chaosgroup.com to investigate what is wrong with it?

Best regards,
Vlado

Vlado, just sent an email with a download link. Tnx very much.

Vlado any discoveries made? tnx

Hey Vlado, just checking in again..

Hi,

Thank you for sending us the file for further investigation. Unfortunately Vlado is very busy at the moment and his reply might be delayed.

I’m checking the scene right now and want to ask you for more details. Which V-Ray version you are using to render and the exact camera name?

Attaching the result that i get from camera 064 and latest official V-Ray 3

Hello
I have the same problem.
The geometry is a chamfer box 3dsmax and she is used as an Xref. The problem occurs when I use a color in the “fog color” and when “fog Multipler” is different from 0.
I currently use 3dsmax 2014 vray 2:40:04.
However, I also had this problem with earlier versions of 3dsmax and vray. (Max 2010 vray 1.5.xx and 2.xx.xx)
I remember to have solved in the past by reconstructing the geometry, but can not remember how …
Or fogmultipler setting to 0 (glass perfectly clear but not real) and adding a little 'green / blue in post production.
In any case, it is really a big problem for me because I work with Xref …
Please fix!

I doubt that this is the same issue. In order to have your particular problem examined, please send a scene to support@chaosgroup.com so that we can see what’s wrong.

Best regards,
Vlado

Hello Vlado
thanks for your reply.
If I collapse the xref in the scene, we have the same problem …
I send you the scene.

Hi Tashko/Vlado.

I’m using 2.40.04.
The camera for that scene is VRayPhysicalCameraMAIN073

I see in your shot that the problem is occurring even with V-Ray 3. I believe all the cameras share the same settings (with the exception of a different custom balance on exterior cams).

Tnx!

Thank you. We are investigating now and as soon as we have any news will post here.

Update: we have logged this issue to our bug tracking system. It seems there is an issue with some go that has been edited, but this have to be confirmed by our developers.
Will keep this thread updated

Have your original window boxes been modified somehow before the rendering process? I mean scaled, edited, merged from other scene which has different units…

We have also managed to get good render results when replaced the current ones. However, we will try to find what the issue is.

The windows boxes started out as just one original Max box. An edit mesh modifier was then applied.

The problem still exists when you just draw a brand new box window - no modifiers - and move it into position in that doorway! The closer a window gets to that jamb/mullion, the issue shows up. None of the other glass panels are showing the problem…

I’ve seen issues similar to this when my system units were very small but it was a pretty big scene.

We will debug this refraction issue and find a way to prevent those artifacts.
As soon as we have any news will post here.

That’s great, Tashko. Thanks much and look forward to hearing any news.

Are there any news?

Unfortunately not yet, we will notify you as soon as any update is available on this refraction issue.