PhotonGI cache

Discussion related to the LuxCore functionality, implementations and API.
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Sharlybg
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Re: PhotonGI cache

Post by Sharlybg »

I should have finally fixed the darker output of PhotonGI. This is an old test rendering
Thanks Dade for the hard work !

When can we test this update ?
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Racleborg
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Re: PhotonGI cache

Post by Racleborg »

I assume we are in a pretty good spot if people complain for rendering this in 10mins ... on a i7 2600 :lol:
Mind blowing stuff :!: :D
epilectrolytics
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Re: PhotonGI cache

Post by epilectrolytics »

Dade wrote: Thu Feb 14, 2019 11:40 am Like I wrote is "mostly" lost because I'm averaging the amount of light reflected by material over the entire hemisphere. This is the average of a constant value for matte, while for glossy is the average of different values. The "shiny" part of gloss is averaged over all the hemisphere (so energy is not lost, it just more "smooth").

If you want to study the problem, you can use indirect cache debug view. If it is not yet clear it is a complete rendering and it should match the output of a normal rendering (splotch-ness aside).

Look this is a rendering with a glossy with 0.0 diffuse and 0.95 specular, PGI rendering:

See how PGI makes the surface look like a diffuse material while the reference is truly glossy. This is the bias introduced in this case however just look at other surfaces, the difference in indirect light is very small (and it is what PGI cache is used for).

Indeed, if all the right wall is black, the bias is huge.
Very interesting!
So for the cache entries directional light is not omitted but averaged which should cause a distributional bias and not one of amount (of light).
I will do some testing later with the newest build, thanks for those examples!
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Sharlybg
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Re: PhotonGI cache

Post by Sharlybg »

I will do some testing later with the newest build, thanks for those examples!
New build with applied fix when where :D ? Need some drugs please :mrgreen:
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lacilaci
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Re: PhotonGI cache

Post by lacilaci »

Sharlybg wrote: Thu Feb 14, 2019 2:01 pm
I will do some testing later with the newest build, thanks for those examples!
New build with applied fix when where :D ? Need some drugs please :mrgreen:
It's up... I'm testing it now...
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lacilaci
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Re: PhotonGI cache

Post by lacilaci »

So, yes.. brightness seems to work now as expected.

250mil photons 10cm lookup 8 depth:
250mil_photons_render.jpg
pathtracing:
path_render.jpg
only 450K photons and 32depth at 30cm lookup radius:
450Kphotons_render.jpg
There seem to be 2 ways of preserving light in photon gi... more depth or more photons. Path depth seem to be less taxing than huge amount of photons.
Also, even 250 000 000 photons at 10cm lookup radius seem to produce fireflies/lightleaks/bleeding.

But it's the only problem left now it looks like
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Sharlybg
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Re: PhotonGI cache

Post by Sharlybg »

SOooooo Cooooool it work like in a dream :D ! Very Good Job Dade the result are even better (less noise).

PGI
PGI.jpg


PGI + Denoise
PGI denoise.jpg
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Dade
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Re: PhotonGI cache

Post by Dade »

I added Russian Roulette to PhotonGI photon tracing, this will reduce the pre-processing time with high max. depth values.
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Sharlybg
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Re: PhotonGI cache

Post by Sharlybg »

I added Russian Roulette to PhotonGI photon tracing, this will reduce the pre-processing time with high max. depth values.
Can i Download now ?
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lacilaci
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Re: PhotonGI cache

Post by lacilaci »

Sharlybg wrote: Thu Feb 14, 2019 5:13 pm
I added Russian Roulette to PhotonGI photon tracing, this will reduce the pre-processing time with high max. depth values.
Can i Download now ?
if you want a windows build, then probably in an hour to be safe. It's still testing.
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