Motion Blur issue with GPU on individual frames in Cycles #76792

Closed
opened 2020-05-15 22:54:08 +02:00 by Michael Hermann · 26 comments

System Information
Operating system: Linux-5.6.10-arch1-1-x86_64-with-arch 64 Bits
Graphics card: GeForce GTX 1080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 440.82

Blender Version
Broken: version: 2.83 (sub 16), branch: master, commit date: 2020-05-14 19:49, hash: f716bb3b71 - same result in 2.82a and 2.90 (downloaded today from the buildbot)
Worked: (newest version of Blender that worked as expected)

Short description of error
When rendering with motion blur, a single frame (usually) shows artifacts when rendering with GPU. (See attached renders. Camera is looking at a RED plane. So red is the correct result.)
I have encountered this quite often when rendering but usually can't share the files or simplify them enough. Here's one that works. - In the attached blend-file I've removed everything I could until it went away. Even removing the plane left of the camera changes the result. So, the reason is not exactly clear to me.

GPU+CPU:
GPU_and_CPU.png
GPU only:
GPU_only.png
CPU only:
CPU_only.png

Exact steps for others to reproduce the error
The best thing to do first is probably to:

  • render frame 1420 using GPU or CPU+GPU (as well as the frames surrounding it).
  • Then, on frame 1420, change the Alpha in the Material in one of the "Card"-Objects.
    The also have a Copy-Scale Constraint. And the first keyframe of the target object is on frame 1420.
    It's best to change different things around and hit F12 every time. Sorry I can't give better instructions, but it's really not clear to me what exactly causes this and which thing exactly triggers it.

Thanks for looking into this! :) Let me know if I can test anything or provide more info.

mBlurBug.blend

**System Information** Operating system: Linux-5.6.10-arch1-1-x86_64-with-arch 64 Bits Graphics card: GeForce GTX 1080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 440.82 **Blender Version** Broken: version: 2.83 (sub 16), branch: master, commit date: 2020-05-14 19:49, hash: `f716bb3b71` - same result in 2.82a and 2.90 (downloaded today from the buildbot) Worked: (newest version of Blender that worked as expected) **Short description of error** When rendering with motion blur, a single frame (usually) shows artifacts when rendering with GPU. (See attached renders. Camera is looking at a RED plane. So red is the correct result.) I have encountered this quite often when rendering but usually can't share the files or simplify them enough. Here's one that works. - In the attached blend-file I've removed everything I could until it went away. Even removing the plane left of the camera changes the result. So, the reason is not exactly clear to me. GPU+CPU: ![GPU_and_CPU.png](https://archive.blender.org/developer/F8537687/GPU_and_CPU.png) GPU only: ![GPU_only.png](https://archive.blender.org/developer/F8537688/GPU_only.png) CPU only: ![CPU_only.png](https://archive.blender.org/developer/F8537689/CPU_only.png) **Exact steps for others to reproduce the error** The best thing to do first is probably to: - render frame 1420 using GPU or CPU+GPU (as well as the frames surrounding it). - Then, on frame 1420, change the Alpha in the Material in one of the "Card"-Objects. The also have a Copy-Scale Constraint. And the first keyframe of the target object is on frame 1420. It's best to change different things around and hit F12 every time. Sorry I can't give better instructions, but it's really not clear to me what exactly causes this and which thing exactly triggers it. Thanks for looking into this! :) Let me know if I can test anything or provide more info. [mBlurBug.blend](https://archive.blender.org/developer/F8537693/mBlurBug.blend)

Added subscriber: @MichaelHermann

Added subscriber: @MichaelHermann

Added subscriber: @iss

Added subscriber: @iss

Can not reproduce this with OpenCL, I suppose you are using CUDA for GPU rendering?

Can not reproduce this with OpenCL, I suppose you are using CUDA for GPU rendering?

Yes, CUDA. I just double-checked again with 2.83 release and the latest 2.90 from the buildbot. The problem still persists.

(2.90 now also shows some weird flickering infinite planes in the viewport - that's new...)
Screenshot from 2020-06-16 22-49-19.png

Yes, CUDA. I just double-checked again with 2.83 release and the latest 2.90 from the buildbot. The problem still persists. (2.90 now also shows some weird flickering infinite planes in the viewport - that's new...) ![Screenshot from 2020-06-16 22-49-19.png](https://archive.blender.org/developer/F8626504/Screenshot_from_2020-06-16_22-49-19.png)

Here is another one. Happens on every frame in the render range. - It seems limited to CUDA.
CPU and now OptiX seem to work fine.

broken:
mBlurFail.png

correct:
nomBlur.png

BugReport.blend

Edit: Blender Version hash: b21ba5e579

Here is another one. Happens on every frame in the render range. - It seems limited to CUDA. CPU and now OptiX seem to work fine. broken: ![mBlurFail.png](https://archive.blender.org/developer/F8653996/mBlurFail.png) correct: ![nomBlur.png](https://archive.blender.org/developer/F8653998/nomBlur.png) [BugReport.blend](https://archive.blender.org/developer/F8654010/BugReport.blend) Edit: Blender Version hash: `b21ba5e579`

Added subscriber: @mano-wii

Added subscriber: @mano-wii

Perhaps I did not understand correctly the steps to reproduce the problem. But I can't reproduce it.


Operating system: Windows-10-10.0.18941 64 Bits
Graphics card: Radeon (TM) RX 480 Graphics ATI Technologies Inc. 4.5.13596 Core Profile Context 20.10.19.02 27.20.1019.2002

Perhaps I did not understand correctly the steps to reproduce the problem. But I can't reproduce it. ---- **Operating system:** Windows-10-10.0.18941 64 Bits **Graphics card:** Radeon (TM) RX 480 Graphics ATI Technologies Inc. 4.5.13596 Core Profile Context 20.10.19.02 27.20.1019.2002

Hi @mano-wii !

You basically have to open the blendfile I added yesterday and e.g. go to Frame 5 and press F12.

But since it's a CUDA problem you'll not be able to reproduce it with your AMD Card.
Please let me know if I can provide more info.

Hi @mano-wii ! You basically have to open the blendfile I added yesterday and e.g. go to Frame 5 and press F12. But since it's a CUDA problem you'll not be able to reproduce it with your AMD Card. Please let me know if I can provide more info.

Just to show it better, here's a screen recording of the issue.
CudaBug.gif

Just to show it better, here's a screen recording of the issue. ![CudaBug.gif](https://archive.blender.org/developer/F8694213/CudaBug.gif)

Added subscriber: @SteffenD

Added subscriber: @SteffenD
Member

Added subscriber: @lichtwerk

Added subscriber: @lichtwerk
Member

Changed status from 'Needs Triage' to: 'Needs User Info'

Changed status from 'Needs Triage' to: 'Needs User Info'
Member

Cannot reproduce here

**System Information**
Operating system: Linux-5.8.18-300.fc33.x86_64-x86_64-with-fedora-33-Thirty_Three 64 Bits
Graphics card: GeForce GTX 970M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 450.66
version: 2.92.0 Alpha, branch: master, commit date: 2020-11-19 09:43, hash: `rB71c6c95aeca4`

(but also checked 2.90)

Since this is lying around for so long now [with no apparent way to proceed], I would kindly ask to give it one last try:

Does this help by any chance?

Cannot reproduce here ``` **System Information** Operating system: Linux-5.8.18-300.fc33.x86_64-x86_64-with-fedora-33-Thirty_Three 64 Bits Graphics card: GeForce GTX 970M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 450.66 version: 2.92.0 Alpha, branch: master, commit date: 2020-11-19 09:43, hash: `rB71c6c95aeca4` ``` (but also checked 2.90) Since this is lying around for so long now [with no apparent way to proceed], I would kindly ask to give it one last try: - latest GPU drivers - Factory Settings - fresh build from https://builder.blender.org/download/ Does this help by any chance?

Thanks for looking at this again. I checked several versions. And it seems to be fixed from 2.90 onward.

Versions tested:
2.91.0 - FIXED [ad58999b0d]
2.90.1 - FIXED
2.83.9 - still broken

Thanks for looking at this again. I checked several versions. And it seems to be fixed from 2.90 onward. Versions tested: 2.91.0 - FIXED [ad58999b0d46] 2.90.1 - FIXED 2.83.9 - still broken
Member

Changed status from 'Needs User Info' to: 'Needs Triage'

Changed status from 'Needs User Info' to: 'Needs Triage'
Member

thx getting back, maybe we can check a commit that could possibly be backported to 2.83 LTS here

thx getting back, maybe we can check a commit that could possibly be backported to 2.83 LTS here

Let me know if I can help.

Let me know if I can help.
Member

Added subscriber: @PratikPB2123

Added subscriber: @PratikPB2123
Member

@MichaelHermann , issue is still there for you ? Can you please check again with 2.83.0 LTS ? (https://builder.blender.org/download/)

@MichaelHermann , issue is still there for you ? Can you please check again with 2.83.0 LTS ? (https://builder.blender.org/download/)

Sorry for the delay. I just tested with the 2.83.16 RC (6dde03eb4a).

Now it renders nothing - only the background color in my testfile from above (from June 28, 2020).
And it's now broken for both GPU and CPU. When I disable Motion Blur, everything renders fine.

It's still all good in 2.93.

Sorry for the delay. I just tested with the 2.83.16 RC (6dde03eb4aa7). Now it renders nothing - only the background color in my testfile from above (from June 28, 2020). And it's now broken for both GPU and CPU. When I disable Motion Blur, everything renders fine. It's still all good in 2.93.
Member

@PratikPB2123 : is this omething you could try to bisect? [try to find which commit fixed this in 2.90]

2.83 LTS will still overlap with 2.93 LTS for about a year more, so would make sense to get the info on the fix commit.
Unless @MichaelHermann will hop on 2.93 [which is around the corner]?

@PratikPB2123 : is this omething you could try to bisect? [try to find which commit fixed this in 2.90] 2.83 LTS will still overlap with 2.93 LTS for about a year more, so would make sense to get the info on the fix commit. Unless @MichaelHermann will hop on 2.93 [which is around the corner]?
Member

Yes, Will bisect it. But Cycles is not included in my ninja build. Any way to include it in ninja build??

Yes, Will bisect it. But Cycles is not included in my ninja build. Any way to include it in ninja build??

Unless @MichaelHermann will hop on 2.93 [which is around the corner]?

I'm usually on stable or even daily builds. So for me personally, this is not an issue anymore, since it's been fixed there. But I'm happy to help solve this for others that might run into this and are on LTS.

> Unless @MichaelHermann will hop on 2.93 [which is around the corner]? I'm usually on stable or even daily builds. So for me personally, this is not an issue anymore, since it's been fixed there. But I'm happy to help solve this for others that might run into this and are on LTS.

Added subscriber: @ThomasDinges

Added subscriber: @ThomasDinges

Changed status from 'Needs Triage' to: 'Resolved'

Changed status from 'Needs Triage' to: 'Resolved'
Thomas Dinges self-assigned this 2021-11-18 17:39:58 +01:00

Closing as resolved, as @MichaelHermann is fine with it working in 2.93 or newer.

Closing as resolved, as @MichaelHermann is fine with it working in 2.93 or newer.
Sign in to join this conversation.
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
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
Overlay
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
Interest
Workbench
Interest: X11
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
No Milestone
No project
No Assignees
7 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#76792
No description provided.