blender
/
blender
75
260
Fork 349
Code Issues 5.9k Pull Requests 544 Projects 19 Wiki Activity

Fix #103977: Cycles handling ray visibility inconsistent for forward and nee #107747

Open
Sebastian Herholz wants to merge 6 commits from sherholz/blender:light-visibility-fix into main
pull from: sherholz/blender:light-visibility-fix
merge into: blender:main

When changing the target branch, be careful to rebase the branch in your fork to match. See documentation.
Conversation 15 Commits 6 Files Changed 9
Sebastian Herholz commented 2023-05-08 17:53:23 +02:00
Collaborator

Reopening the PR to fix the ray visibility inconsistency on light sources (#103977)

Reopening the PR to fix the ray visibility inconsistency on light sources (#103977)
Brecht Van Lommel was assigned by Sebastian Herholz 2023-05-08 17:53:23 +02:00
Sergey Sharybin was assigned by Sebastian Herholz 2023-05-08 17:53:23 +02:00
Sebastian Herholz added 1 commit 2023-05-08 17:53:33 +02:00
Sebastian Herholz commented 2023-05-08 17:55:18 +02:00
Poster
Collaborator

@brecht to reduce the additional per state memory consumption I was thinking of using RGBE compressed values.
http://www.graphics.cornell.edu/online/formats/rgbe/

What do you think?

@brecht to reduce the additional per state memory consumption I was thinking of using RGBE compressed values. http://www.graphics.cornell.edu/online/formats/rgbe/ What do you think?
Sebastian Herholz added 1 commit 2023-05-08 21:26:23 +02:00
Sebastian Herholz commented 2023-05-08 21:28:23 +02:00
Poster
Collaborator

Added SpectrumRGBE support, that stores a float3 into an int32 using 8bit RGB and a shared exponent.
No visual difference between using float3.

Added SpectrumRGBE support, that stores a float3 into an int32 using 8bit RGB and a shared exponent. No visual difference between using float3.
Sergey Sharybin changed title from Fix T103977: Cycles handling ray visibility inconsistent for forward and nee to Fix #103977: Cycles handling ray visibility inconsistent for forward and nee 2023-05-09 09:01:07 +02:00
Sergey Sharybin commented 2023-05-09 09:05:09 +02:00
Owner

@blender-bot package

@blender-bot package
Blender Bot commented 2023-05-09 09:05:12 +02:00
Collaborator

Package build started. Download here when ready.

Package build started. [Download here](https://builder.blender.org/download/patch/PR107747) when ready.
Sebastian Herholz added 1 commit 2023-05-09 09:26:39 +02:00
buildbot/vexp-code-patch-coordinator Build done. Details
6696aa979b Cycles: SpectrumRGBE: oneAPI float3 fix
Sergey Sharybin requested changes 2023-05-09 09:30:47 +02:00
Sergey Sharybin left a comment
Owner

Did not deeply check on the algorithm/math yet, was trying to get the patch to testable state. There is some technical feedback so far.

Would need to have a closer look to see if we can probably lower the memory impact further.

Please also check the output of the buildbot: https://builder.blender.org/admin/#/builders/136/builds/1170

Did not deeply check on the algorithm/math yet, was trying to get the patch to testable state. There is some technical feedback so far. Would need to have a closer look to see if we can probably lower the memory impact further. Please also check the output of the buildbot: https://builder.blender.org/admin/#/builders/136/builds/1170
intern/cycles/kernel/light/visibility.h
@ -0,0 +11,4 @@
ccl_device_inline SpectrumRGBE SpectrumToSpectrumRGBE(const Spectrum &spec)
{
SpectrumRGBE specRGBE;
char *specRGBEPtr = (char *)&specRGBE;
Sergey Sharybin commented 2023-05-09 09:14:37 +02:00
Owner

Can we define SpectrumRGBE as

struct SpectrumRGBE {
  uint8_t r, g, b, e;
};

and avoid such memory casts, and casts between signed/unsigned char?

This also seems to a bit arbitrary place to have such utility functions. Within the current file structure it seems types_spectrum.h is the most fitted place for it.

Can we define `SpectrumRGBE ` as ``` struct SpectrumRGBE { uint8_t r, g, b, e; }; ``` and avoid such memory casts, and casts between signed/unsigned `char`? This also seems to a bit arbitrary place to have such utility functions. Within the current file structure it seems `types_spectrum.h` is the most fitted place for it.
Sebastian Herholz commented 2023-05-09 09:49:14 +02:00
Poster
Collaborator

sure no problem.

sure no problem.
Sebastian Herholz commented 2023-05-09 10:05:31 +02:00
Poster
Collaborator

@Sergey done.
I am not sure if you can compress the data even more.
The positive side on this approach is that we can realize handling scalar ray types light interactions straight forward instead of only binary ones.

@Sergey done. I am not sure if you can compress the data even more. The positive side on this approach is that we can realize handling scalar ray types light interactions straight forward instead of only binary ones.
Sebastian Herholz commented 2023-05-09 10:13:28 +02:00
Poster
Collaborator

Another thing worth considering is moving the conversion methods to a different place (not into visibility.h).
Do you have a good suggestion for it?

Another thing worth considering is moving the conversion methods to a different place (not into `visibility.h`). Do you have a good suggestion for it?
Sergey Sharybin commented 2023-09-11 16:11:57 +02:00
Owner

The immediate thought is kernel/util/color.h. There is already spectrum_to_rgb so intuitively feels like spectrum_to_spectrum_rgbe could fit there as well.

The immediate thought is `kernel/util/color.h`. There is already `spectrum_to_rgb` so intuitively feels like `spectrum_to_spectrum_rgbe` could fit there as well.
Sebastian Herholz commented 2023-05-09 09:47:40 +02:00
Poster
Collaborator

@blender-bot package

@blender-bot package
Blender Bot commented 2023-05-09 09:47:43 +02:00
Collaborator

Package build started. Download here when ready.

Package build started. [Download here](https://builder.blender.org/download/patch/PR107747) when ready.
Sebastian Herholz added 1 commit 2023-05-09 10:03:56 +02:00
buildbot/vexp-code-patch-coordinator Build done. Details
7a4f223c47 Cycles: SpectrumRGBE moved from char* to uint8_t
Sebastian Herholz commented 2023-05-09 10:07:07 +02:00
Poster
Collaborator

@blender-bot package

@blender-bot package
Blender Bot commented 2023-05-09 10:07:10 +02:00
Collaborator

Package build started. Download here when ready.

Package build started. [Download here](https://builder.blender.org/download/patch/PR107747) when ready.
Sebastian Herholz added 1 commit 2023-05-09 13:54:36 +02:00
buildbot/vexp-code-patch-coordinator Build done. Details
c0edb57875 Cycles: SpectrumRGBE potential Metal fix
Sebastian Herholz commented 2023-05-09 13:55:18 +02:00
Poster
Collaborator

@blender-bot package

@blender-bot package
Blender Bot commented 2023-05-09 13:55:21 +02:00
Collaborator

Package build started. Download here when ready.

Package build started. [Download here](https://builder.blender.org/download/patch/PR107747) when ready.
Sebastian Herholz added 1 commit 2023-05-09 14:33:10 +02:00
buildbot/vexp-code-patch-coordinator Build done. Details
f1bce9b0a9 Cycles: SpectrumRGBE potential Metal fix part 2
Sebastian Herholz commented 2023-05-09 14:33:23 +02:00
Poster
Collaborator

@blender-bot package

@blender-bot package
Blender Bot commented 2023-05-09 14:33:26 +02:00
Collaborator

Package build started. Download here when ready.

Package build started. [Download here](https://builder.blender.org/download/patch/PR107747) when ready.
Brecht Van Lommel commented 2023-05-09 15:50:36 +02:00
Owner

If this can solve the problem without serious downsides it will be great, but I think this needs to be checked more closely.

  • What is the performance impact of this on CPU and GPU? I would not be surprised if there is a measurable performance impact, but maybe it's not so bad.
  • 8 bits is not a lot, I expect this will lead to noticeable banding and precision loss in some cases. Especially when combined with compositing. For example one a large plane, if one color channel is fixed, and another has a gradient from 0 to 1, then imagine that will show up as banding in the render buffer?
If this can solve the problem without serious downsides it will be great, but I think this needs to be checked more closely. * What is the performance impact of this on CPU and GPU? I would not be surprised if there is a measurable performance impact, but maybe it's not so bad. * 8 bits is not a lot, I expect this will lead to noticeable banding and precision loss in some cases. Especially when combined with compositing. For example one a large plane, if one color channel is fixed, and another has a gradient from 0 to 1, then imagine that will show up as banding in the render buffer?
Sebastian-Herholz commented 2023-05-09 19:40:50 +02:00
Collaborator

@brecht I will do some deeper evaluation and report the results later.
On my first tests on my RTX2070 I did not measure any performance difference.

I think if there is one, it will only happen on the GPU, and then it will be mainly caused by the bigger state.
Additional computing is only performed when I light source with visibility flags it hit, and in all the standard scenes, this feature is not used so often (e.g., barbershop scene (2 light sources) and Dark Interior (also 2 light sources)).

About RGBE, I am quite surprised that it works so well. In my test scene, I couldn't even see a difference in the EXR images when I made a diff (float3 vs RGBE) and pulled up the exposure. I will post the images later.
I think one reason why the compression works well, in this case, is that we are not working with really high dynamic range values, mainly BSDF_evals/pdfs.
These values only get large if the BSDF has a large value and the PDF is suuuper low.

I will try to set up a scene like the one you described.

@brecht I will do some deeper evaluation and report the results later. On my first tests on my RTX2070 I did not measure any performance difference. I think if there is one, it will only happen on the GPU, and then it will be mainly caused by the bigger state. Additional computing is only performed when I light source with visibility flags it hit, and in all the standard scenes, this feature is not used so often (e.g., barbershop scene (2 light sources) and Dark Interior (also 2 light sources)). About RGBE, I am quite surprised that it works so well. In my test scene, I couldn't even see a difference in the EXR images when I made a diff (float3 vs RGBE) and pulled up the exposure. I will post the images later. I think one reason why the compression works well, in this case, is that we are not working with really high dynamic range values, mainly BSDF_evals/pdfs. These values only get large if the BSDF has a large value and the PDF is suuuper low. I will try to set up a scene like the one you described.
Weizhen Huang reviewed 2023-07-17 09:10:40 +02:00
intern/cycles/kernel/integrator/surface_shader.h
@ -246,3 +246,3 @@
if (bsdf_pdf != 0.0f) {
bsdf_eval_accum(result_eval, sc->type, eval * sc->weight);
if (!_surface_shader_exclude(sc->type, light_shader_flags)) {
Weizhen Huang commented 2023-07-17 09:10:40 +02:00
Collaborator

I wonder, shouldn't the function surface_shader_bsdf_eval_pdfs() just below it follow the same logic and be corrected too?

I wonder, shouldn't the function `surface_shader_bsdf_eval_pdfs()` just below it follow the same logic and be corrected too?
Sergey Sharybin commented 2023-09-11 16:13:26 +02:00
Owner

@Sebastian-Herholz Any progress with the benchmarking and testing? Apart from performance there are two extra topics which I am wondering here:

  • The state size increase on high-end cards
  • The "future-proofness" of the solution: is it how we'd want to solve the problem when Cycles goes spectral?
@Sebastian-Herholz Any progress with the benchmarking and testing? Apart from performance there are two extra topics which I am wondering here: * The state size increase on high-end cards * The "future-proofness" of the solution: is it how we'd want to solve the problem when Cycles goes spectral?

Reviewers

Sergey Sharybin requested changes 2023-05-09 09:30:47 +02:00
Some checks failed
buildbot/vexp-code-patch-coordinator Build done.
Details
This pull request has changes conflicting with the target branch.
  • intern/cycles/kernel/integrator/shade_background.h
  • intern/cycles/kernel/integrator/shade_light.h
  • intern/cycles/kernel/integrator/shade_surface.h
  • intern/cycles/kernel/integrator/surface_shader.h
Sign in to join this conversation.
Reviewers
Request review
No reviewers
Sergey Sharybin
Labels
Apply labels
Clear labels   
Interest
Alembic
   
Interest
Animation & Rigging
   
Interest
Asset Browser
   
Interest
Asset Browser Project Overview
   
Interest
Audio
   
Interest
Automated Testing
   
Interest
Blender Asset Bundle
   
Interest
BlendFile
   
Interest
Collada
   
Interest
Compatibility
This issue affects/is about backward or forward compatibility   
Interest
Compositing
   
Interest
Core
   
Interest
Cycles
   
Interest
Dependency Graph
   
Interest
Development Management
   
Interest
EEVEE & Viewport
   
Interest
Freestyle
   
Interest
Geometry Nodes
   
Interest
Grease Pencil
   
Interest
ID Management
   
Interest
Images & Movies
   
Interest
Import Export
   
Interest
Line Art
   
Interest
Masking
   
Interest
Metal
   
Interest
Modeling
   
Interest
Modifiers
   
Interest
Motion Tracking
   
Interest
Nodes & Physics
   
Interest
OpenGL
   
Interest
Overrides
   
Interest
Performance
   
Interest
Physics
   
Interest
Pipeline, Assets & IO
   
Interest
Platforms, Builds & Tests
   
Interest
Python API
   
Interest
Render & Cycles
   
Interest
Render Pipeline
   
Interest
Sculpt, Paint & Texture
   
Interest
Text Editor
   
Interest
Translations
   
Interest
Triaging
   
Interest
Undo
   
Interest
USD
   
Interest
User Interface
   
Interest
UV Editing
   
Interest
VFX & Video
   
Interest
Video Sequencer
   
Interest
Virtual Reality
   
Interest
Vulkan
  
Interest: Wayland
  
Legacy
Blender 2.8 Project
   
Legacy
Milestone 1: Basic, Local Asset Browser
   
Legacy
OpenGL Error
  
Meta
Good First Issue
   
Meta
Papercut
   
Meta
Retrospective
   
Meta
Security
Issues relating to security: https://wiki.blender.org/wiki/Process/Vulnerability_Reports
  
Module
Animation & Rigging
   
Module
Core
   
Module
Development Management
   
Module
EEVEE & Viewport
   
Module
Grease Pencil
   
Module
Modeling
   
Module
Nodes & Physics
   
Module
Pipeline, Assets & IO
   
Module
Platforms, Builds & Tests
   
Module
Python API
   
Module
Render & Cycles
   
Module
Sculpt, Paint & Texture
   
Module
Triaging
   
Module
User Interface
   
Module
VFX & Video
  
Platform
FreeBSD
   
Platform
Linux
   
Platform
macOS
   
Platform
Windows
  
Priority
High
   
Priority
Low
   
Priority
Normal
   
Priority
Unbreak Now!
  
Status
Archived
   
Status
Confirmed
   
Status
Duplicate
   
Status
Needs Info from Developers
   
Status
Needs Information from User
   
Status
Needs Triage
   
Status
Resolved
  
Type
Bug
   
Type
Design
   
Type
Known Issue
   
Type
Patch
   
Type
Report
   
Type
To Do
No Label
Interest
Alembic
Interest
Animation & Rigging
Interest
Asset Browser
Interest
Asset Browser Project Overview
Interest
Audio
Interest
Automated Testing
Interest
Blender Asset Bundle
Interest
BlendFile
Interest
Collada
Interest
Compatibility
Interest
Compositing
Interest
Core
Interest
Cycles
Interest
Dependency Graph
Interest
Development Management
Interest
EEVEE & Viewport
Interest
Freestyle
Interest
Geometry Nodes
Interest
Grease Pencil
Interest
ID Management
Interest
Images & Movies
Interest
Import Export
Interest
Line Art
Interest
Masking
Interest
Metal
Interest
Modeling
Interest
Modifiers
Interest
Motion Tracking
Interest
Nodes & Physics
Interest
OpenGL
Interest
Overrides
Interest
Performance
Interest
Physics
Interest
Pipeline, Assets & IO
Interest
Platforms, Builds & Tests
Interest
Python API
Interest
Render & Cycles
Interest
Render Pipeline
Interest
Sculpt, Paint & Texture
Interest
Text Editor
Interest
Translations
Interest
Triaging
Interest
Undo
Interest
USD
Interest
User Interface
Interest
UV Editing
Interest
VFX & Video
Interest
Video Sequencer
Interest
Virtual Reality
Interest
Vulkan
Interest: Wayland
Legacy
Blender 2.8 Project
Legacy
Milestone 1: Basic, Local Asset Browser
Legacy
OpenGL Error
Meta
Good First Issue
Meta
Papercut
Meta
Retrospective
Meta
Security
Module
Animation & Rigging
Module
Core
Module
Development Management
Module
EEVEE & Viewport
Module
Grease Pencil
Module
Modeling
Module
Nodes & Physics
Module
Pipeline, Assets & IO
Module
Platforms, Builds & Tests
Module
Python API
Module
Render & Cycles
Module
Sculpt, Paint & Texture
Module
Triaging
Module
User Interface
Module
VFX & Video
Platform
FreeBSD
Platform
Linux
Platform
macOS
Platform
Windows
Priority
High
Priority
Low
Priority
Normal
Priority
Unbreak Now!
Status
Archived
Status
Confirmed
Status
Duplicate
Status
Needs Info from Developers
Status
Needs Information from User
Status
Needs Triage
Status
Resolved
Type
Bug
Type
Design
Type
Known Issue
Type
Patch
Type
Report
Type
To Do
Milestone
Set milestone
Clear milestone
No items
No Milestone
Projects
Set Project
Clear projects
No project
Assignees
Assign users
Clear assignees
No Assignees
Brecht Van Lommel
Sergey Sharybin
6 Participants
Notifications
Due Date
The due date is invalid or out of range. Please use the format 'yyyy-mm-dd'.

No due date set.

Dependencies

No dependencies set.

Reference: blender/blender#107747
There is no content yet.
Delete Branch "sherholz/blender:light-visibility-fix"

Deleting a branch is permanent. Although the deleted branch may exist for a short time before cleaning up, in most cases it CANNOT be undone. Continue?