vray universal render settigns, but getting artifacts, light leaks

[lukx]

I set LC subdivs to 4000 sample size to 0.001 but still getting those strange light leaks, splotches:
walls have thickness, materials aren't 255 white.

[PIXELBOX_SRO]

i had this as well...usually happens when the light has to trave quite a lot between bounces.....i had to abandon the scene cos i was not getting a good quality no matter what i did, those artifacts were always there.
I still struggle with understanding of how some settings in vray work....the only way for me sometimes to tackle the noise or these artifacts is turning the setting waaaay up

try checking store direct light
try setting prefiltering to 100

[lukx]

yeah, I got vray light planes in windows and there is not sun light, room is quite big so I guess its' because of this travel distance you mentioned. Setting LC to 8000 starting to help.

[peterguthrie]

Isnt this exactly what the new retrace threshold option in vray 2 is for?

[vlado]

Yep, it's useful in exactly such cases. Other than that, 0.001 for the light cache size seems way too low, a higher value might actually work better.

Best regards,
Vlado

[lukx]

ok I'll take a look at it.

[jophus14]

Lukx: Did you ever solve the issue? I am having the same problem, but it only happens when rendering out frames for a animation and not the still test images. Thanks

I'm trying not to jack your thread, but since this thread is already created, I figured that it may benefit both of us if the issue gets solved.

Vlado: I am pre-calculating the LC and IRR map prior to rendering out the final frames. Is there anything that I should look out for in the settings that might help with this issue? Thanks

[vlado]

Take a look at the light cache itself (select it as both primary and secondary engine). If it is very noisy around the problem spots, then you'll need to increase the light cache subdivs.

Best regards,
Vlado

[jophus14]

Unticking "Store Direct Light" in the Light Cache drop-down fixed the light leak problems. Now I have to work on getting a quality set of images without killing my render time per frame.

[vlado]

Hm, for the images above it would be odd if you need to uncheck this option - it looks like it should work fine. If you wish you can send the scene to us at vray@chaosgroup.com so that our support guys can check what's wrong.

Best regards,
Vlado