LuxCoreRender Forums

here the scene
https://we.tl/t-0gsJXscmDi

marcatore wrote: Sun Sep 30, 2018 12:27 pm I've problem with DLCS.
This is what I've


Lux2.1 alpha4 using GPU
All default settings


There are that blobs.
Any suggestions?

Don't use the synthetic Sky but HDRI/IBL.
Check more about it here: viewtopic.php?f=9&t=472&start=10#p4808

kintuX wrote: Sun Sep 30, 2018 9:00 pm

marcatore wrote: Sun Sep 30, 2018 12:27 pm I've problem with DLCS.
This is what I've


Lux2.1 alpha4 using GPU
All default settings


There are that blobs.
Any suggestions?

Don't use the synthetic Sky but HDRI/IBL.
Check more about it here: viewtopic.php?f=9&t=472&start=10#p4808

Well your own test there actually shows that it is not sky or hdri but a combination of sun and sky or hdri or flat color.

For example I rarely use HDRI cause they only make sense in some cases. For example in most archviz I do use sun and sky system, so what do I do if I want to use sun&sky and many interior lights that could benefit from DLCS?

lacilaci wrote: Mon Oct 01, 2018 6:15 am Well your own test there actually shows that it is not sky or hdri but a combination of sun and sky or hdri or flat color.

For example I rarely use HDRI cause they only make sense in some cases. For example in most archviz I do use sun and sky system, so what do I do if I want to use sun&sky and many interior lights that could benefit from DLCS?

Well I did further tests after, with alpha3 on interior, and it appeared that, when using HDRI with Sun, those splotches were gone. True, I didn't post any results yet (because i didn't thoroughly test it further), but here's a quickie:
Had simply changed World's Sky for HDRI (HDRI 360° Saalfelden, Austria) --- Gain: 3000
Personally, i prefer HDRI/IBL simply because of artistic freedom.

DLCS is not design for this kind of scene or i'm completly wrong

Sharlybg wrote: Mon Oct 01, 2018 9:53 am DLCS is not design for this kind of scene or i'm completly wrong

It should still not cause artifacts. Seems like a bug to me.

maybe it's a problem of mostly uniform lighing that sky creates or completely uniform from flat color? Confusing lightcache?

It should still not cause artifacts. Seems like a bug to me.

Yes of course
I mean people should use correct tool for better perf ! if it is also cool if such test show buggs

lacilaci wrote: Mon Oct 01, 2018 10:24 am maybe it's a problem of mostly uniform lighing that sky creates or completely uniform from flat color? Confusing lightcache?

I think that is a sampling problem: DLSC trys to establish if the light is visible with very few rays (in order to speed up the pre-processing phase). But trying to establish if the Sky light source is visible with only ~16 rays can lead to false positive/negative in indoor scenes. I will check but I'm pretty sure this is the explanation.

The solution shouldn't be too complex: for instance I could handle Sky light as special case requiring more rays or always include Sky in the cache entry, etc.

Maybe the DLSC building phase could also use the visibility map, if it was computed?