LuxCoreRender Forums

Dade wrote: Wed Feb 13, 2019 11:19 am

lacilaci wrote: Wed Feb 13, 2019 8:41 am Another problem, I don't know what are the latest changes to materials (I've read on github material list fix so I assumed now all materials work)

Nothing has changed, cache entries are still created only on matte and glossy material (due to a now fixed bug, before they were created on metal material too).

lacilaci wrote: Wed Feb 13, 2019 8:41 am But, now even my matte wall is not able to gather GI samples from sky (note that this scene contains only sky) EDIT: it actually does gather photon gi but it is very very dark, in older builds it wasn't that bad.
Screenshot from 2019-02-13 09-47-23.png

This was the result of a typo, causing the lookup radius parameter being used instead of the lookup normal threshold parameter. This was stopping PhotonGI from creating entries on some or even all surfaces. I should have fixed this problem.

Ok, so there is no plan to use cache on metals? Even when they're rough?
And more important, coating material...

Will test latest fixes after build is done

Just sayin, the problems with caustic cache and sun+sky are still there (it does not depend on light strategy).

lacilaci wrote: Wed Feb 13, 2019 11:42 am Ok, so there is no plan to use cache on metals? Even when they're rough?
And more important, coating material...

Nothing has changed: first you get the core algorithm right than you can think to extend the number of supported materials.

Caustics test (no reflections?) reference
& a PMGI test (even tho translucency isn't in yet, result seems promising, t~5min) Noticed that
1. PM isn't using all the threads (67%),
2. the more photons there are the slower further rendering (samples/sec) gets
3. with latest version it's only running single threaded...


Also, have found couple of videos worth watching:
- Advanced global illumination using photon mapping (SIGGRAPH 2008 Courses)
- VRay for 3ds Max - Photon Mapping
Can kind of softening, which is observed in VRay video, be achieved?

3. with latest version it's only running single threaded...

You render for 5mins just with only one thread ?

Ok, so the black rendering problem is fixed in latest build but the brightness difference is still present just as my previous post on this topic.

kintuX wrote: Wed Feb 13, 2019 1:31 pm 1. PM isn't using all the threads (67%),
3. with latest version it's only running single threaded...

There is something in your system going wrong, it normally uses 100% of CPU. Are you running out of memory or something similar ?

EDIT: see my next post.

kintuX wrote: Wed Feb 13, 2019 1:31 pm 2. the more photons there are the slower further rendering (samples/sec) gets

Only if you use the caustic cache, just disable the caustic cache (useless 99.99% of the times) and the number of photons will not matter: indirect and caustic cache are 2 quite different items (even if they are the result of a common pre-process).

lacilaci wrote: Wed Feb 13, 2019 2:50 pm Ok, so the black rendering problem is fixed in latest build but the brightness difference is still present just as my previous post on this topic.

So glossy, black and light leaks rendering are fixed and only the light intensity difference is left

Dade wrote: Wed Feb 13, 2019 3:12 pm

lacilaci wrote: Wed Feb 13, 2019 2:50 pm Ok, so the black rendering problem is fixed in latest build but the brightness difference is still present just as my previous post on this topic.

So glossy, black and light leaks rendering are fixed and only the light intensity difference is left

Well light leaks seem to still appear if you use small lookup radius (10-15cm is too low for regular interior, 30cm is still not enough in larger open space)
But more photons to fill space will help there. I'm trying to figure out how many photons could be good enough on average to help combat with that.

The brightness issue is always present and no amount of photons helps with that (more photons will only help reduce light leaks and get better color balance)

The thing with lookup radius is that even large lookup 40cm renders very very fast and doesn't need too many photons to help with leaks.

My assumption right now is that for previews and stills use less photons and larger lookup and for animations I guess you would need more photons and maybe a slightly smaller lookup....?