EEVEE Geometry nodes Point Separate node causes motion blur glitches #87165

New Issue

Samuel Peterson · 2021-04-03T16:28:48+02:00

Samuel Peterson commented

2021-04-03 16:28:48 +02:00

System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: GeForce GTX 1060 6GB/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 461.92

Blender Version
Broken: version: 2.93.0 Alpha, branch: master, commit date: 2021-04-01 15:32, hash: 76cdcc2bca
Worked: (newest version of Blender that worked as expected)

Short description of error
If you scatter objects using points and separate them using a mask that changes over time, the objects appear consistent between frames as expected but their motion blur is glitching all over the place in renders.
whether this mask is derived from point distance to a moving camera or a weight pain that is being animated over time does not seem to matter, the issue lies clearly within point separate. both these types of changing masks are included in the geometry nodes tree within frames.

Exact steps for others to reproduce the error
render an image at frame 360 of the blend file with one of the two frames in the geometry nodes connected to the output.
motion blur is enabled, amount of steps doesn't matter

glitchy motion blur:

approximation of expected result by removing point separate, please ignore distant objects (still includes camera motion blur)

.blend file
blendbug.blend

**System Information** Operating system: Windows-10-10.0.19041-SP0 64 Bits Graphics card: GeForce GTX 1060 6GB/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 461.92 **Blender Version** Broken: version: 2.93.0 Alpha, branch: master, commit date: 2021-04-01 15:32, hash: `76cdcc2bca` Worked: (newest version of Blender that worked as expected) **Short description of error** If you scatter objects using points and separate them using a mask that changes over time, the objects appear consistent between frames as expected but their motion blur is glitching all over the place in renders. whether this mask is derived from point distance to a moving camera or a weight pain that is being animated over time does not seem to matter, the issue lies clearly within point separate. both these types of changing masks are included in the geometry nodes tree within frames. **Exact steps for others to reproduce the error** render an image at frame 360 of the blend file with one of the two frames in the geometry nodes connected to the output. motion blur is enabled, amount of steps doesn't matter **glitchy motion blur:** ![blendbug1step.png](https://archive.blender.org/developer/F9918948/blendbug1step.png) **approximation of expected result by removing point separate, please ignore distant objects (still includes camera motion blur)** ![blendbug2.png](https://archive.blender.org/developer/F9918944/blendbug2.png) **.blend file** [blendbug.blend](https://archive.blender.org/developer/F9918942/blendbug.blend)

Samuel Peterson commented

2021-04-03 16:28:48 +02:00

Added subscriber: @craggolly

Hans Goudey commented

2021-04-28 06:33:42 +02:00

Added subscriber: @HooglyBoogly

Hans Goudey commented

2021-04-28 06:33:42 +02:00

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

Hans Goudey commented

2021-04-28 06:33:42 +02:00

Thanks for the report. I created D11104 to investigate this. It turns out the join node wasn't copying the instance IDs used for proper motion blur. I think it wasn't a problem without the point separate node since the join node has a special case for when there is only one input geometry set.

Thanks for the report. I created [D11104](https://archive.blender.org/developer/D11104) to investigate this. It turns out the join node wasn't copying the instance IDs used for proper motion blur. I think it wasn't a problem without the point separate node since the join node has a special case for when there is only one input geometry set.

blender-admin commented

2021-04-28 06:37:27 +02:00

This issue was referenced by 7e678c3096

This issue was referenced by 7e678c30964c4c0d9d2c020f25e8ac717211c208

Hans Goudey commented

2021-04-28 06:38:29 +02:00

Changed status from 'Confirmed' to: 'Resolved'

Hans Goudey closed this issue

2021-04-28 06:38:29 +02:00

Hans Goudey self-assigned this 2021-04-28 06:38:29 +02:00

Thomas Dinges added this to the 2.93 LTS milestone 2023-02-07 18:46:14 +01:00

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EEVEE Geometry nodes Point Separate node causes motion blur glitches #87165