blender/blender

Weird Motion Blur with Simulation Nodes #112061

New Issue

Open

opened 2023-09-06 23:25:46 +02:00 by Marco · 4 comments

Marco commented

2023-09-06 23:25:46 +02:00

Member

Blender Version
Broken: 3.6.2

Short description of error
Motion Blur doesn't work properly with Geometry Nodes instances.
As shown in the rendered video, the motion blur seems to give weird results, the motion trails of the instanced particles from the Geometry Nodes (and Simulation Nodes) setup don't seem to follow their direction properly.

Exact steps for others to reproduce the error
Test.blend

Open file
Hit play to bake simulation until let's say frame 45
Render frame 45

**Blender Version** Broken: 3.6.2 **Short description of error** Motion Blur doesn't work properly with Geometry Nodes instances. As shown in the rendered video, the motion blur seems to give weird results, the motion trails of the instanced particles from the Geometry Nodes (and Simulation Nodes) setup don't seem to follow their direction properly. <video src="/attachments/bbf95da0-1813-4ccb-bf2b-c2d18462c1db" title="animation.mp4" controls></video> **Exact steps for others to reproduce the error** [Test.blend](/attachments/b6370519-e6e5-49e4-ab65-7b3ada4f331e) - Open file - Hit play to bake simulation until let's say frame 45 - Render frame 45

1.2 MiB

animation.mp4

11 MiB

Marco added the

labels 2023-09-06 23:25:47 +02:00

Pratik Borhade commented

2023-09-07 08:06:52 +02:00

Member

Thanks for the report. I can confirm.

Thanks for the report. I can confirm.

Pratik Borhade added

Render & Cycles

Nodes & Physics

and removed

labels 2023-09-07 08:07:15 +02:00

Iliya Katushenock commented

2023-09-07 14:12:07 +02:00

Member

Okay, this not a bug. First: Geometry Nodes use ID attribute as way to define each unique element for procedurally-animated geometry. So motion blur interpolate elements with the same ID value. But as i know this work only for point cloud domain. I might do not know a many things about render eevee / cycles (and why eevee are work correct, but cycles not work). But as i see (see attached my video), your geometry even not correct for unique IDs. I not sure about instances domain and other potential limitation, but multiple elements with the same ID - is just autor mistake.

Okay, this not a bug. First: Geometry Nodes use ID attribute as way to define each unique element for procedurally-animated geometry. So motion blur interpolate elements with the same ID value. But as i know this work only for point cloud domain. I might do not know a many things about render eevee / cycles (and why eevee are work correct, but cycles not work). But as i see (see attached my video), your geometry even not correct for unique IDs. I not sure about instances domain and other potential limitation, but multiple elements with the same ID - is just autor mistake.

2023-09-07 15-06-06.mp4

9.9 MiB

Marco commented

2023-09-07 18:41:11 +02:00

Author

Member

Thank you for the reply. Scratched my head a bit and got it working!
Basically used the Set ID node to give instances a fixed ID.
Although I would like to report that the Distribute Points on Faces automatically gives weird ID numbers, as reported here too #103325.

Here is the fixed version for anybody who needs it:
Test.zip

Thank you for the reply. Scratched my head a bit and got it working! Basically used the Set ID node to give instances a fixed ID. Although I would like to report that the Distribute Points on Faces automatically gives weird ID numbers, as reported here too https://projects.blender.org/blender/blender/issues/103325. ![untitled.jpg](/attachments/203f206c-cdf8-493c-95f6-636a7caa7655) Here is the fixed version for anybody who needs it: [Test.zip](/attachments/904655ab-a07c-4302-8636-242ce5349266)

untitled.jpg

181 KiB

124 KiB

Iliya Katushenock commented

2023-09-07 18:43:42 +02:00

Member

This not related, didn't deep into your node tree, but think you just duplicate points...

This not related, didn't deep into your node tree, but think you just duplicate points...

Fischer referenced this issue

2024-04-02 04:22:42 +02:00

Cycles point cloud ID get incorrect motionblur result #120153

Brecht Van Lommel added

and removed

labels 2024-06-14 16:00:39 +02:00

Sign in to join this conversation.

No Label

Animation & Rigging

Automated Testing

Blender Asset Bundle

Dependency Graph

Development Management

Images & Movies

Motion Tracking

Nodes & Physics

Pipeline, Assets & IO

Platforms, Builds & Tests

Render & Cycles

Render Pipeline

Sculpt, Paint & Texture

Video Sequencer

Viewport & EEVEE

Virtual Reality

Asset Browser Project

Blender 2.8 Project

Milestone 1: Basic, Local Asset Browser

Good First Issue

Animation & Rigging

Development Management

Nodes & Physics

Pipeline, Assets & IO

Platforms, Builds & Tests

Render & Cycles

Sculpt, Paint & Texture

Viewport & EEVEE

Needs Info from Developers

Needs Information from User

No Milestone

No project

No Assignees

3 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#112061

No description provided.