22002 Max 2012 - Light leaks between objects

[leotchest]

Seen several posts on this, but cant see why this kind of thing is still happening in a lot of my renders ? It usually occurs when two objects are close to each other.
You get this wierd incorrect light glow/blotchy thing happening at the gap between the two objects. In this typical example, it is between the back of the toilet & the wall.
I have tried changing the GI Surface ID of the objects & tried different methods of GI, Currently using IM & LC

[Dariusz Makowski (Dadal)]

I think it could be bat material in a way, have u try to render using grey material? - Disaplecement can cause bugs and issues like that

From other hand try enablind detail enchancement for IM that should fix it. If no disable secondary GI(LC in ur case) and render with just IM, see if they still pop up. If they do try setting up tresholds to 0.1 0.1 0.1. Is ur scene correctly scaled ? Mean 1 cm = 1 cm etc etc...

Thanks, bye.

[leotchest]

the scene scale is correct, always correct. I tried rendering with IM & Brute force for secondary GI - but still getting the problem. I will try with a grey material and some of the other suggestions & post again later on. thx

[Dariusz Makowski (Dadal)]

Its IM then I guess, just enable detail enchacement see if that fix it...

[vlado]

Do your walls have an actual thickness? What is the shadow bias parameter for the VRaySun light?

Best regards,
Vlado

[leotchest]

the walls do all have thickness. vray sun shadow bias is default at 20cm

[vlado]

vray sun shadow bias is default at 20cm

Ok, maybe that's why... try a lower value (even 0.0 if necessary) and see if it helps.

Best regards,
Vlado

[Dariusz Makowski (Dadal)]

Maybe in object proporties or material u simply have boosted ur GI to like 20 or so so it causes massive issues?

[leotchest]

... try a lower value (even 0.0 if necessary) and see if it helps.

That certainly seems to be helping - the more i dial it down, the better it gets. I went all the way down to 0.0, but i still do get some (less than before, but still some) of the unwanted light leak effects (e.g. behind some pillows where they contact the wall, or where the TV is close to the wall). I have not messed around with any of the object based GI settings (except to change some GI id's)

[vlado]

Ok then; if you like you can get me a part of your scene to vlado@chaosgroup.com and I'll take a closer look at what's going on. Btw, have you changed the "secondary rays bias" option in the V-Ray settings?

Best regards,
Vlado

[leotchest]

Great - thanks. Currently, secondary ray bias is set to 0.0
In terms of general settings, I am using the plugin "solidrocks"

[Subburb]

Hi Leo, can you please post a screencap of your solidrocks options panel ? have you some interpolation options activated into SolidRocks options ?

[leotchest]

Here is a screencap.
However, i did try reseting Vray and rendering with just IM & Brute Force. I still got light leaks.

[Subburb]

Hmmm that's weird... did you tried to check the "check sample visibility" for IM ?

[vlado]

Well, I couldn't reproduce the issue in the scene that Leo sent, so I'm still scratching my head about this one... there were some missing plugins though, I should try to get them first.

Best regards,
Vlado