Irradiance Light Explosions

[mokiloke]

Every animation we have done over the last year that uses irradiance maps often results in explosions of light, see example images. They are sometimes quite random with the same frame showing no problems on following renders. The light artifact is the saved into the irradiance map which basically ruins the whole saved irradiance map. Has anyone had this problem, we have experienced it over a number of jobs and different versions of vray.

[vlado]

There could be a number of reasons for this, e.g. incorrectly set up materials, reflective caustics, etc. So if you can get me one example scene to vlado@chaosgroup.com I'll try to see what's causing it.

Best regards,
Vlado

[aphex79]

we have had this problem too..

[Aldaryn]

For the first two images, I'd say its some nasty GI caustics, even from incorrectly setup shaders, like vlado said. Overbright shaders, the sun itself, etc. in most cases the cause of blownout irradiance map samples come down to a simple reason: there is something in the scane small and bright eneugh, to mess up the bounced rays unfortunate eneugh to hit that thing.

And for the last one, hmm, wow... better send that to Vlado.

best regards,

A.

[natty]

That last one screams Max Raytrace..

[Clifton Santiago]

Its not" light explosions" is just a caustics problems or something. It looks like you are setting things up wrong and using raytrace materials. I've never had this problem, so the problem is most likely not Vray. If you are convinced that IR is the problem, then switch to QMC (Brute Force to you).

[mokiloke]

Thanks for the replys everyone. Vlado is having a look at it for me, always a quick response, for the first 2. Vlado said to turn off the vray sun which cured the problem but seems like a strange solution as i now wont get highlights in water and off cars i think. I cut the scene down to 3 object and 3 vray material so this one wasnt raytrace mat related.

Just having a look at the 3rd one again now.

This problem has been the bane of our existence for the last few years, im glad i finally posted about it.

[paulison]

i dig that last image and would like to know how to acheive such an effect

The other stuff does look like standard material issues to me anyway. yucky raytrace

EDIT: i just noticed that it wasnt a raytrace mat problem. Maybe scale or geometry errors?. Why would the sun cause this? too bright?. very weird