Lighting issue - large pixelated lighting

[pascalls]

Hi,

I was recently rendering animation of a very large project, bulk of geometry came from revit, and was getting strange lighting errors that are clearly visible on the attached vray raw lighting pass (final pass with the light error in the bottom right corner). The problem appeared on few different places in the building (different max files), all of them directly lit by the sun.

Has anyone experienced any simmilar issues?
What can be the cause of this error?


Please let me know if you need any further info and ill be happy to provide.
Thanks a lot!

Max2017 with vray 3.5 on Win10

[Miro]

Can you share the scene or a part of it to support@chaosgroup.com?

[Vizioen]

Besides this meme, I have nothing of value to to add to this thread. I'm sorry.


Edit: some tips maybe:

- Normals ok?
- Overlapping geometry?
- Does it render ok when you isolate the faulty geometry?

[dlparisi]

What version of VRay? I know you said 3.5 but what release? Maybe this is the problem... https://forums.chaosgroup.com/showth...ctionality-bug

[davision]

as someone said -- overlapping geometry is a likely cause. that mesh/grid ceiling could be the culprit. hide it and see if it fixes things -- if it does, then carefully analyze that mesh. it might be too duplicate pieces attached into one.

[pascalls]

^REVIT.... was that the reason that caused previous civilization to collapse? where are the ancient aliens when you need them...
Unfortunatley on large projects there is simply no way to avoid having to deal with revit one way or another. 90% of my work is based on revit datasets.

Normals ok, no overlapping geometry and it renders fine when isolated.
Also renders fine if i delete the sun as in there are no problems visible on lighting passes and this is what ive done to be able to render this particular clip as i didnt have time to troubleshoot.

I am inclined to think that this is somehow related to the issues with the object scale that some revit geometry exibits, kind of thing where even after applying xform you cant get UVW to scale correctly on the object or shading groups to show/render properly.
have no idea, only guessing.


@miroslav

Ill try to find this version of the file and will send it to you.
Thank you!

[pascalls]

Im on v3.50.04
Thank you for the link!

It looks like that my problem is caused by the sun (problem went away when i deleted the sun but left all other lights, some 50+ rect vray lights), not rect light and my sampling rate pass looks ok, as well as every other pass apart from lighting passes

[pascalls]

as someone said -- overlapping geometry is a likely cause. that mesh/grid ceiling could be the culprit. hide it and see if it fixes things -- if it does, then carefully analyze that mesh. it might be too duplicate pieces attached into one.

Definitley not overlaping geometry. I rendered some 10sec of this clip and there were no flickering as you would get with overlaping faces but just rock solid pixelated lighting coming from the sun as in the pic above.

The pattern seems to appear on areas directly lit by the sun or with the sun light that goes through windows and, as in the pic above, semi transparent canopy.

[davision]

Did you try adjusting shadow bias in the sun params? try going real low first.