PhotonGI cache

Discussion related to the LuxCore functionality, implementations and API.
User avatar
Dade
Developer
Developer
Posts: 5672
Joined: Mon Dec 04, 2017 8:36 pm
Location: Italy

Re: PhotonGI cache

Post by Dade »

Dade wrote: Wed Feb 13, 2019 3:10 pm
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 ?
On a second tough, there is a single thread bottle neck, it is related to the build of visibility map. Do you get the under 100% load when you see this type of log message ?

Code: Select all

[LuxCore][0.690] PhotonGI trace visibility particles thread count: 12
[LuxCore][2.822] PhotonGI visibility entries: 180224/229376 (78%)
[LuxCore][2.822] PhotonGI visibility hits: 39/490654 (0.0092%)
[LuxCore][5.100] PhotonGI visibility entries: 376832/425984 (88%)
[LuxCore][5.100] PhotonGI visibility hits: 94/1013888 (0.0092%)
[LuxCore][7.417] PhotonGI visibility entries: 573440/622592 (92%)
[LuxCore][7.417] PhotonGI visibility hits: 197/1537369 (0.0458%)
But the build of visibility map should be long only if you are using a very small look up radius and/or some ultra-detailed geometry like a forest, etc.
Support LuxCoreRender project with salts and bounties
User avatar
lacilaci
Donor
Donor
Posts: 1969
Joined: Fri May 04, 2018 5:16 am

Re: PhotonGI cache

Post by lacilaci »

Here's an example
250K photons+cache size (A bit too low but to demonstrate leaks)

250K photons 2min rendering, lookup 10cm:
2min10cm.jpg
250K photons 2min rendering, lookup 40cm:
2min40cm.jpg
note that larger lookup is actually faster and also kills leaks/bleeding.

Those leaks actually look a lot like some sort of reflection almost.. always in corners.
User avatar
lacilaci
Donor
Donor
Posts: 1969
Joined: Fri May 04, 2018 5:16 am

Re: PhotonGI cache

Post by lacilaci »

And here are my "lucky numbers" (at least it seem to work in testscenes so far)

Photon count: 10 000 000
depth: 8
max size: 600 000
lookup radius: 40cm

4 minute rendering:
A.jpg
3 minute rendering:
B.jpg
but yeah, testscenes... I'm super busy right now to make new project (and my current work renders(also using luxcore :)) are under NDA and they aren't interiors to test)
User avatar
lacilaci
Donor
Donor
Posts: 1969
Joined: Fri May 04, 2018 5:16 am

Re: PhotonGI cache

Post by lacilaci »

10 minute + 9sec denoising at 4K... same cache settings as before
If this was on gpu, 10 minute would be final quality! (Well, probably a little more since no complex materials etc.. but you get the idea)
C.jpg
User avatar
lacilaci
Donor
Donor
Posts: 1969
Joined: Fri May 04, 2018 5:16 am

Re: PhotonGI cache

Post by lacilaci »

From what I'm seeing, there are only 2 problems left

Those extremely bright looking lightleaks might creep in and need to be watched for, if they were at least subtle, settings could be a lot more forgiving.

the brightness difference even in areas that are in plain sight are a bit worrying too. Again a subtle difference or color balance difference is ok, but atm it's just kinda weird looking...
User avatar
Sharlybg
Donor
Donor
Posts: 3101
Joined: Mon Dec 04, 2017 10:11 pm
Location: Ivory Coast

Re: PhotonGI cache

Post by Sharlybg »

Photon count: 10 000 000
max size: 600 000
lookup radius: 40cm
Dade am i wrong or you already planned to make theses number settings automatic ?
Support LuxCoreRender project with salts and bounties

Portfolio : https://www.behance.net/DRAVIA
User avatar
Dade
Developer
Developer
Posts: 5672
Joined: Mon Dec 04, 2017 8:36 pm
Location: Italy

Re: PhotonGI cache

Post by Dade »

lacilaci wrote: Wed Feb 13, 2019 3:43 pm Those leaks actually look a lot like some sort of reflection almost.. always in corners.
In my opinion, the correct name is fireflies, not light leaks. They are spikes in a cache entry that has received a very small amount of photons (and one of them was "firefly" photon). Increasing the number of traced photons reduces the problem like in a normal rendering.

Increasing there radius also reduce the problem because you are averaging a larger number of photons (with the same result of tracing more photons).

Like in an normal rendering, I could implement some kind of variance clamping on cache entries (but just spending 15 more seconds tracing photons is a better solution than adding another parameters). It could be mostly intended for very fast previews.
Support LuxCoreRender project with salts and bounties
User avatar
Dade
Developer
Developer
Posts: 5672
Joined: Mon Dec 04, 2017 8:36 pm
Location: Italy

Re: PhotonGI cache

Post by Dade »

Sharlybg wrote: Wed Feb 13, 2019 4:27 pm
Photon count: 10 000 000
max size: 600 000
lookup radius: 40cm
Dade am i wrong or you already planned to make theses number settings automatic ?
It is a possibility, Visual map entries are already built with an automatic stop condition. Indirect cache could have a similar condition (Caustic is a different beast).
Support LuxCoreRender project with salts and bounties
User avatar
lacilaci
Donor
Donor
Posts: 1969
Joined: Fri May 04, 2018 5:16 am

Re: PhotonGI cache

Post by lacilaci »

Dade wrote: Wed Feb 13, 2019 4:33 pm
lacilaci wrote: Wed Feb 13, 2019 3:43 pm Those leaks actually look a lot like some sort of reflection almost.. always in corners.
In my opinion, the correct name is fireflies, not light leaks. They are spikes in a cache entry that has received a very small amount of photons (and one of them was "firefly" photon). Increasing the number of traced photons reduces the problem like in a normal rendering.

Increasing there radius also reduce the problem because you are averaging a larger number of photons (with the same result of tracing more photons).

Like in an normal rendering, I could implement some kind of variance clamping on cache entries (but just spending 15 more seconds tracing photons is a better solution than adding another parameters). It could be mostly intended for very fast previews.
I see, but why are they only in corners? Some sort of, out of control bouncing? Low energy loss?
User avatar
Dade
Developer
Developer
Posts: 5672
Joined: Mon Dec 04, 2017 8:36 pm
Location: Italy

Re: PhotonGI cache

Post by Dade »

lacilaci wrote: Wed Feb 13, 2019 3:59 pm And here are my "lucky numbers" (at least it seem to work in testscenes so far)

Photon count: 10 000 000
depth: 8
max size: 600 000
lookup radius: 40cm

4 minute rendering:
A.jpg
3 minute rendering:
B.jpg

but yeah, testscenes... I'm super busy right now to make new project (and my current work renders(also using luxcore :)) are under NDA and they aren't interiors to test)
Side note: try to export a scene and move around the camera in LuxCoreUI ... an hardware vendor could setup a nearly real-time demo station by using some serious hardware.
Support LuxCoreRender project with salts and bounties
Post Reply