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Env light Cache performance

Posted: Fri Jan 24, 2020 12:36 pm
by Sharlybg
While preparing a 3D project to test Luxcore Vs Octane i fall on this strange behaviour of Env light cache feature. in fact when enable it bring to noisier/darker image than without.



No Envcache 71 scs
No__Env__cache__1.30.jpg

Envcache 90 scs
Env__cache__1.30.jpg
Strangely it is the kind of scene where it should shine.

Re: Env light Cache performance

Posted: Fri Jan 24, 2020 4:40 pm
by Dade
Try to do a test without sun, only sky. Sun is not affected by Env. cache.

P.S. I expect the same result but with "interference" from sun noise.

Re: Env light Cache performance

Posted: Fri Jan 24, 2020 5:12 pm
by Sharlybg
Dade wrote: Fri Jan 24, 2020 4:40 pm Try to do a test without sun, only sky. Sun is not affected by Env. cache.

P.S. I expect the same result but with "interference" from sun noise.
There is no sun in fact in this test. it is pure HDRi lighting accross both render.

Re: Env light Cache performance

Posted: Fri Jan 24, 2020 6:12 pm
by Dade
Sharlybg wrote: Fri Jan 24, 2020 5:12 pm
Dade wrote: Fri Jan 24, 2020 4:40 pm Try to do a test without sun, only sky. Sun is not affected by Env. cache.

P.S. I expect the same result but with "interference" from sun noise.
There is no sun in fact in this test. it is pure HDRi lighting accross both render.
It is one of that HDR with a very bright single pixel (i.e. sun), you can increase (a lot) the resolution of Env. cache maps (and probably go out of memory at some point) or scale down the HDR, you will surprise how much the noise is reduced.

P.S. I have described the solution to this problem a while ago but it needs still to be implemented.

Re: Env light Cache performance

Posted: Fri Jan 24, 2020 9:56 pm
by Sharlybg
Thanks for the explanation. Don't understand "" scale down the HDRi""" . My current hdri is 1k should i go to 0.3k or sometjing like that ?

Re: Env light Cache performance

Posted: Fri Jan 24, 2020 11:02 pm
by Dade
Sharlybg wrote: Fri Jan 24, 2020 9:56 pm Thanks for the explanation. Don't understand "" scale down the HDRi""" . My current hdri is 1k should i go to 0.3k or sometjing like that ?
For a test, there should be a large difference. Anyway, to get less noise in that image, the sun+sky combo should be the best one (with PGI and Env. cache).