Re: PhotonGI cache
Posted: Thu Sep 12, 2019 12:23 pm
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PhotonGI cache
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Re: PhotonGI cache
Posted: Fri Sep 13, 2019 9:47 pm
I like the idea of the control over the number of bounces before using PGI cache.lacilaci wrote: Wed Sep 11, 2019 4:55 pm I have this idea that might be a bit stupid but maybe not:
Would it be possible to control after how many bounces is photongi used? Maybe this would help with some reflection artifacting or leaks?
So maybe have 1 or 2 bounces brute force and afterwards sample from cache(a control exposed to the user).
The reason is that sometimes luxcore performs well in interior even without photongi but some areas are a bit "too deep" in terms of gi so they could benefit from photongi. However enabling cache might bring some artifacting even to areas which were ok and fast before. So I have to pick between artifacts and speed...
In my head I think this could help protect areas exposed to few bounces but still give speedup for hard to reach areas.
In the meantime you could try to enable Add Light Tracing with Glossiness Threshold: 1.
According to my tests it helps to illuminate hard to reach areas. After all PGI uses Light Tracing too.
Cons: doesn't work with Matte (but works with Glossy or Disney with max. roughness) and darkens speculars (without PSR)
Re: PhotonGI cache
Posted: Sat Sep 14, 2019 6:56 am
hm, never tried such high threshold..provisory wrote: Fri Sep 13, 2019 9:47 pmI like the idea of the control over the number of bounces before using PGI cache.lacilaci wrote: Wed Sep 11, 2019 4:55 pm I have this idea that might be a bit stupid but maybe not:
Would it be possible to control after how many bounces is photongi used? Maybe this would help with some reflection artifacting or leaks?
So maybe have 1 or 2 bounces brute force and afterwards sample from cache(a control exposed to the user).
The reason is that sometimes luxcore performs well in interior even without photongi but some areas are a bit "too deep" in terms of gi so they could benefit from photongi. However enabling cache might bring some artifacting even to areas which were ok and fast before. So I have to pick between artifacts and speed...
In my head I think this could help protect areas exposed to few bounces but still give speedup for hard to reach areas.
In the meantime you could try to enable Add Light Tracing with Glossiness Threshold: 1.
According to my tests it helps to illuminate hard to reach areas. After all PGI uses Light Tracing too.
Cons: doesn't work with Matte (but works with Glossy or Disney with max. roughness) and darkens speculars (without PSR)
Re: PhotonGI cache
Posted: Sun Sep 15, 2019 6:29 am
But it also makes me think.. Isn't it necessary to have lighttracing threshold at 1 so that all materials are included for correct sds with PSR build?
Re: PhotonGI cache
Posted: Fri Aug 14, 2020 12:09 pm
coming back to PGI...
I have a scene with a glossy wodden floor and curtains with glossy translucent material and they're noiser than the walls and other objects are using matte materials.
I've seen, using the the PGI debug mode "show indirect/path mix" that floor and curtains are red.
I've tried to replicate the room in a simple scene with just one material and I've tried to render (in debug mode) the room as a full glossy room.
I've tried to set the glossiness threshold to have a "blue" render and this is the result compared to a matte material.
glossy material
matte material
Is it normal? Isn't it possible to caching more with glossy materials?
I have a scene with a glossy wodden floor and curtains with glossy translucent material and they're noiser than the walls and other objects are using matte materials.
I've seen, using the the PGI debug mode "show indirect/path mix" that floor and curtains are red.
I've tried to replicate the room in a simple scene with just one material and I've tried to render (in debug mode) the room as a full glossy room.
I've tried to set the glossiness threshold to have a "blue" render and this is the result compared to a matte material.
glossy material
matte material
Is it normal? Isn't it possible to caching more with glossy materials?
Re: PhotonGI cache
Posted: Fri Aug 14, 2020 12:11 pm
What are you using as glossy roughness and PGI roughness threshold ?marcatore wrote: Fri Aug 14, 2020 12:09 pm Is it normal? Isn't it possible to caching more with glossy materials?
Re: PhotonGI cache
Posted: Fri Aug 14, 2020 12:24 pm
higher material roughness value , more red image
as soon as I go little over the PGI glossiness threshold, the image becomes more blue.
If I put the PGI glossiness threshold over the mat roughness, the image becomes (correctly) full red
Re: PhotonGI cache
Posted: Fri Aug 14, 2020 8:15 pm
another question:
if I launch a final render with border, the PGI calculation is reduced by the area I'm rendering or it's always a full frame calculation?
if I launch a final render with border, the PGI calculation is reduced by the area I'm rendering or it's always a full frame calculation?
Re: PhotonGI cache
Posted: Sat Aug 15, 2020 6:21 am
another question:
as PGI is a simplified representation of the lighting...is it mandatory to consider also the normal map when the system decides if use PGI or Brute force?
as PGI is a simplified representation of the lighting...is it mandatory to consider also the normal map when the system decides if use PGI or Brute force?
Re: PhotonGI cache
Posted: Sat Aug 15, 2020 10:15 am
This is the expected behavior:marcatore wrote: Fri Aug 14, 2020 12:24 pm higher material roughness value , more red image
as soon as I go little over the PGI glossiness threshold, the image becomes more blue.
- high roughness => nearly diffuse reflection, rays spread in all directions, can hit a near or far object => half way between red and blue.
- low roughness => nearly specular, like a mirror, all rays fired in nearly the same direction, very likely to always hit the same object (and at the same distance) => mostly red or blue (no half way).