No particle position updates when rendering animation using cycles + motion blur + center on frame #62439

New Issue

Bengt Vagnhammar · 2019-03-11T11:27:24+01:00

Bengt Vagnhammar commented

2019-03-11 11:27:24 +01:00

System Information
Operating system: Ubuntu 18.10
Graphics card: Asus GTX 1080 TI

Blender Version
Broken:
2.80 beta, a0f2923fd8, 2019-03-08 21:52
Worked: (optional)

Short description of error
Particles don't move during render animation when cycles + motion blur + center on frame is used.
They do move when running the animation in the viewport (at least before the animation has been rendered).
Switching Render->Motion Blur->Position to "Start on Frame" makes the particles move correctly during render.

Exact steps for others to reproduce the error

Open attached .blend file.
Select Render->Render Animation from the menu. => Particles don't fall.
Change settings panel: Render->Motion Blur->Position from "Center on Frame" to "Start on Frame".
Do: Render->Render Animation again. This time the particles will fall correctly.
stationary_particles_bug.blend
- Edit 2019-03-11 21:09 --
  Tried force fields "wind" and "vortex" too. No particle movement for either of "Start/Center/End on Frame" with motion blur + cycles.
  Only gravity (of the ones I've tested) seems to work with "Start on Frame".

**System Information** Operating system: Ubuntu 18.10 Graphics card: Asus GTX 1080 TI **Blender Version** Broken: 2.80 beta, a0f2923fd821, 2019-03-08 21:52 Worked: (optional) **Short description of error** Particles don't move during render animation when cycles + motion blur + center on frame is used. They do move when running the animation in the viewport (at least before the animation has been rendered). Switching Render->Motion Blur->Position to "Start on Frame" makes the particles move correctly during render. **Exact steps for others to reproduce the error** * Open attached .blend file. * Select Render->Render Animation from the menu. => Particles don't fall. * Change settings panel: Render->Motion Blur->Position from "Center on Frame" to "Start on Frame". * Do: Render->Render Animation again. This time the particles will fall correctly. [stationary_particles_bug.blend](https://archive.blender.org/developer/F6800842/stationary_particles_bug.blend) - Edit 2019-03-11 21:09 -- Tried force fields "wind" and "vortex" too. No particle movement for either of "Start/Center/End on Frame" with motion blur + cycles. Only gravity (of the ones I've tested) seems to work with "Start on Frame".

Bengt Vagnhammar commented

2019-03-11 11:27:24 +01:00

Added subscriber: @btvr

Sergey Sharybin was assigned by Sebastian Parborg

2019-03-11 14:48:49 +01:00

Sergey Sharybin commented

2019-03-14 16:41:35 +01:00

This roots back to d1be30f7, which was needed here for the studio.
The reason this specific issue happens is because cache gets invalidated when object is tagged for geometry update. This happens in both recent blender.27 builds and in master (copy-on-write always does geometry re-evaluation on F12, since that creates a new graph).

Keep in mind, most reliable way of rendering particles is to bake them.
Will try to find a solution to make particles to work similar to 2.79 release.

This roots back to d1be30f7, which was needed here for the studio. The reason this specific issue happens is because cache gets invalidated when object is tagged for geometry update. This happens in both recent blender.27 builds and in master (copy-on-write always does geometry re-evaluation on F12, since that creates a new graph). Keep in mind, most reliable way of rendering particles is to bake them. Will try to find a solution to make particles to work similar to 2.79 release.

Sergey Sharybin was unassigned by Dalai Felinto

2019-12-23 16:34:56 +01:00

Dalai Felinto commented

2019-12-23 16:34:56 +01:00

Added subscriber: @Sergey

Richard Antalik commented

2020-01-24 23:05:28 +01:00

Added subscriber: @iss

Richard Antalik commented

2020-01-24 23:05:28 +01:00

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

Richard Antalik commented

2020-01-24 23:05:28 +01:00

I have re-triaged this report and can not reproduce it.
Can you please check if this is still an issue in latest build?
https://builder.blender.org/download/

I have re-triaged this report and can not reproduce it. Can you please check if this is still an issue in latest build? https://builder.blender.org/download/

Sebastian Parborg commented

2020-02-05 14:19:48 +01:00

Added subscriber: @ZedDB

Sebastian Parborg commented

2020-02-05 14:19:48 +01:00

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

Sebastian Parborg closed this issue

2020-02-05 14:19:48 +01:00

Sebastian Parborg self-assigned this 2020-02-05 14:19:48 +01:00

Sebastian Parborg commented

2020-02-05 14:19:48 +01:00

Since last asking for information it has been 7 or more days, due to the policy of our bug tracker we will have to archive the report until the requested information is given.

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No particle position updates when rendering animation using cycles + motion blur + center on frame #62439