Light leaks and errors

[stevesideas]

Im having problems with a scene im rendering out at the moment. As you can see, my settings are all set fairly high. It seems only to be happening in the higher detail areas. Seems that the gi is getting a bit confused. I have tried setting the vrayproperties id's to different numbers and all the other things that can cause light leaks and problems but with no luck.

Any ideas ?

Happy Christmas and New Year by the way

[voltron7]

Do you get the errors if you disable secondary bounces?

[stevesideas]

No. Dont seem to be there now with secondary bounce off. The detailed areas are still shaded strangley...kind of splotchy. Maybe I should increase the interp samples ?!

[voltron7]

Yes, upping the samples might help, but it sounds like maybe something needs attention in the light cache settings? Hopefully some more knowledgeable v-ray users will throw in here...

[stevesideas]

Thats my thought, but there isnt that much to change on the lightcache side of things that makes that much difference. Sample size is already lower than I usually use for most situations and lightcache subs look about right for the size of image 1280x720. Not sure what else to try really..

[vlado]

You can try to change the light cache scale to "World" (and adjust the sample size accordingly); the other thing to try is turning off the "Store direct light" option.

Best regards,
Vlado

[stevesideas]

Thanks. I'll try those 2 things. If I was wanting to do an animation of this scene where just the camera moves, "world" wouldnt be a good option would it ?

[vlado]

Actually in that case, the "World" scale would be the right one to use (like in the tutorial here: http://www.spot3d.com/vray/help/150S...ials_imap2.htm)

Best regards,
Vlado

[stevesideas]

Oh, how little it seems I know...I always use "screen" for my animations! I'll try the world scale. Is there a good scale setting to start off with ? I am working in millimeters.

[vlado]

About 10-20 cm should probably be ok.

Best regards,
Vlado

[voltron7]

light cache

I didn't catch it in your settings at first glance, but I have been having better results turning off "store direct light" option Vlado just mentioned.
(at least for still images)

[3DMK]

Try turning on the 'Detail Enhancement' option on the irradiance map. This option was developed to overcome just the sort of problems you are having in the detailed areas.

It works great for very detailed & small/fine geometry

Cheers

[stevesideas]

I tend to steer clear of detail enhancement as it tends to push render times sky high. Im wondering..would it be possible to lower the normal irr settings to sort the larger areas of lighting and then turn on detail enhancement for the smaller areas without increasing render times too much ?

[Morbid Angel]

if the radius on your detail enhancement is not very large it will work quite well.

[3DMK]

Im wondering..would it be possible to lower the normal irr settings to sort the larger areas of lighting and then turn on detail enhancement for the smaller areas without increasing render times too much ?

That's exactly how it's supposed to be used!
I usually set up the detail enhancement to world scale & use values between 20mm up to 100mm depending on the scene.

Just remember this method uses brute force DMC & the subdivision multiplier for this is a percentage of the irradiance maps hemispherical subdivisions.
If your irradiance map HSph are high then you may want to decrease the value of the detail enhancement multiplier to alleviate long render times.

Cheers