PhotonGI cache

Discussion related to the Engine functionality, implementations and API.
User avatar
Dade
Developer
Developer
Posts: 3243
Joined: Mon Dec 04, 2017 8:36 pm
Location: Italy

Re: PhotonGI cache

Post by Dade » Sat Mar 30, 2019 4:51 pm

Dade wrote:
Fri Mar 29, 2019 5:02 pm
P.S. I'm investigating the strange color outside left and right wall.
This is interesting, the problem is due to Intel Oidn:

color.png

Upper left image is the raw version while upper right the is the denoised one. The red color bleeding is caused by Oidn.

The color bleeding seems to disappear with more samples and may be caused by the camera motion blur (i.e. noise on albedo AOV).
Support LuxCoreRender project with salts and bounties

User avatar
Dade
Developer
Developer
Posts: 3243
Joined: Mon Dec 04, 2017 8:36 pm
Location: Italy

Re: PhotonGI cache

Post by Dade » Mon Apr 01, 2019 9:32 am

Dade wrote:
Sat Mar 30, 2019 4:51 pm
This is interesting, the problem is due to Intel Oidn:
FYI, It looks like the problem is not related to camera motion blur but a problem of Oidn with totally black surfaces. You can find the details here: https://github.com/OpenImageDenoise/oidn/issues/22

It is a corner case but it is better know.
Support LuxCoreRender project with salts and bounties

User avatar
epilectrolytics
Donor
Donor
Posts: 570
Joined: Thu Oct 04, 2018 6:06 am

Re: PhotonGI cache

Post by epilectrolytics » Sun Apr 07, 2019 8:23 am

Dade wrote:
Thu Mar 28, 2019 10:32 am
I added the support for persistent PhotonGI cache.
What about Blender integration of this, is there some progress or is it very difficult and will take more time?
Will the motion-blur-approach work for straight camera moves only or for curved ones too?
MBPro 15" 16GB i7-4850HQ GT750M, MacOS 10.13.6 & Win10Pro PC 16GB Ryzen 2700X, 2 x RTX 2070

User avatar
B.Y.O.B.
Developer
Developer
Posts: 2997
Joined: Mon Dec 04, 2017 10:08 pm
Location: Germany
Contact:

Re: PhotonGI cache

Post by B.Y.O.B. » Sun Apr 07, 2019 11:35 am

epilectrolytics wrote:
Sun Apr 07, 2019 8:23 am
What about Blender integration of this, is there some progress or is it very difficult and will take more time?
Not sure how to expose this in the best way yet.
Right now I'm working on a script that lets you render an animation without reloading the session, so you only have to load the scene once and the rest is done via sceneedit (like in the Blender viewport, e.g. when you move the camera around).
Support LuxCoreRender project with salts and bounties

User avatar
epilectrolytics
Donor
Donor
Posts: 570
Joined: Thu Oct 04, 2018 6:06 am

Re: PhotonGI cache

Post by epilectrolytics » Sun Apr 07, 2019 2:07 pm

Sounds reasonable, thanks!
MBPro 15" 16GB i7-4850HQ GT750M, MacOS 10.13.6 & Win10Pro PC 16GB Ryzen 2700X, 2 x RTX 2070

Luxart
Posts: 49
Joined: Tue Feb 13, 2018 10:14 am

Re: PhotonGI cache

Post by Luxart » Thu Apr 11, 2019 4:53 am

In animations Photon GI causes flickering. How to avoid it or Is Photon GI useful only for still images :?:

User avatar
epilectrolytics
Donor
Donor
Posts: 570
Joined: Thu Oct 04, 2018 6:06 am

Re: PhotonGI cache

Post by epilectrolytics » Thu Apr 11, 2019 6:10 am

Hi Luxart,
first the persistent cache must be integrated into Blender.
It's not yet ready, see comment above by B.Y.O.B.
MBPro 15" 16GB i7-4850HQ GT750M, MacOS 10.13.6 & Win10Pro PC 16GB Ryzen 2700X, 2 x RTX 2070

Luxart
Posts: 49
Joined: Tue Feb 13, 2018 10:14 am

Re: PhotonGI cache

Post by Luxart » Thu Apr 11, 2019 6:45 am

In animations Photon GI causes flickering. How to avoid it or Is Photon GI useful only for still images :?:
epilectrolytics wrote:
Thu Apr 11, 2019 6:10 am
Hi Luxart,
first the persistent cache must be integrated into Blender.
It's not yet ready, see comment above by B.Y.O.B.
I think Persistent Photon GI cache is for fly through animations(only camera edit - which is rarely useful).

In general animation (edit all objects) flickering problem occurs.

User avatar
epilectrolytics
Donor
Donor
Posts: 570
Joined: Thu Oct 04, 2018 6:06 am

Re: PhotonGI cache

Post by epilectrolytics » Thu Apr 11, 2019 7:30 am

Sorry for misunderstanding, you're right.
General animation of objects is not going to work with PGI.
Building of the cache introduces bias which partly depends on the photon distribution.
A moving object affects the photon distribution which will then in each frame lead to a different bias on the not moving parts showing as flickering.
It's similar to noise in path tracing which you can get an persistent pattern of with a fixed seed value on unmoving parts but never on moving ones.
Only when nothing moves but the camera persistent cache can be applied.
MBPro 15" 16GB i7-4850HQ GT750M, MacOS 10.13.6 & Win10Pro PC 16GB Ryzen 2700X, 2 x RTX 2070

User avatar
Dade
Developer
Developer
Posts: 3243
Joined: Mon Dec 04, 2017 8:36 pm
Location: Italy

Re: PhotonGI cache

Post by Dade » Thu Apr 11, 2019 9:21 am

Luxart wrote:
Thu Apr 11, 2019 6:45 am
In general animation (edit all objects) flickering problem occurs.
Have you done some test ? It would be interesting to see the results. I mean, it would be an expected problem but it is hard to see any difference between "brute force path tracing" alone and brute "force path tracing+PGI" renderings so it is possible that any flicker could be solved by just adjusting some parameter.
Support LuxCoreRender project with salts and bounties

Post Reply