Cycles Motion Blur 'explodes' #62655

New Issue

Closed

opened 2019-03-16 14:03:06 +01:00 by Fred Fonkle · 11 comments

Fred Fonkle commented

2019-03-16 14:03:06 +01:00

System Information
Operating system: Kubuntu 18.10
Graphics card: GTX970

Blender Version
Broken: 2.80, 3600bb79d0, 2019-03-15
Worked: (?)

Short description of error

In a scene with an animated camera which is tracking to an animated target, motion blur 'explodes' on certain frames.

Exact steps for others to reproduce the error

I have a .blend file attached; it contains a simple scene with a cube, an animated camera tracking to an animated empty. When rendering frame 39 with Cycles and motion blur enabled (default settings), the motion blur 'explodes'. Other frames seem fine. If I disconnect the Environment Texture node from the Background in the world shader, the motion blur seems fine.

I am not 100% sure this isn't some sub-frame gimbal lock issue I should avoid in animation, but since it manifested often with Blender 2.8 I suspect this is a bug.

ExplodingMotionBlurFrame39-v001.blend

**System Information** Operating system: Kubuntu 18.10 Graphics card: GTX970 **Blender Version** Broken: 2.80, 3600bb79d05d, 2019-03-15 Worked: (?) **Short description of error** In a scene with an animated camera which is tracking to an animated target, motion blur 'explodes' on certain frames. **Exact steps for others to reproduce the error** I have a .blend file attached; it contains a simple scene with a cube, an animated camera tracking to an animated empty. When rendering frame 39 with Cycles and motion blur enabled (default settings), the motion blur 'explodes'. Other frames seem fine. If I disconnect the Environment Texture node from the Background in the world shader, the motion blur seems fine. I am not 100% sure this isn't some sub-frame gimbal lock issue I should avoid in animation, but since it manifested often with Blender 2.8 I suspect this is a bug. [ExplodingMotionBlurFrame39-v001.blend](https://archive.blender.org/developer/F6834446/ExplodingMotionBlurFrame39-v001.blend)

Fred Fonkle commented

2019-03-16 14:03:06 +01:00

Author

Added subscriber: @Fonkle

Added subscriber: @Fonkle

William Reynish commented

2019-03-18 13:33:47 +01:00

Added subscribers: @brecht, @WilliamReynish

Added subscribers: @brecht, @WilliamReynish

Brecht Van Lommel was assigned by William Reynish

2019-03-18 13:33:47 +01:00

William Reynish commented

2019-03-18 13:33:47 +01:00

Can reproduce this. Seems strange.

@brecht feel free to re-assign if the issue is not with Cycles itself.

Can reproduce this. Seems strange. @brecht feel free to re-assign if the issue is not with Cycles itself.

Fred Fonkle commented

2019-03-21 14:32:40 +01:00

Author

Update: motion blur does not 'explode' when I set Motion Blur 'Position' to either 'Start on Frame' or 'End on Frame'.

Update: motion blur does not 'explode' when I set Motion Blur 'Position' to either 'Start on Frame' or 'End on Frame'.

Jacques Lucke commented

2019-03-25 17:00:28 +01:00

Member

Added subscriber: @JacquesLucke

Added subscriber: @JacquesLucke

Jacques Lucke commented

2019-03-25 17:00:28 +01:00

Member

With Start on Frame the problem appears when 0.18 <= shutter <= 0.35.
With Center on Frame it happens when 0.36 <= shutter.

With `Start on Frame` the problem appears when `0.18 <= shutter <= 0.35`. With `Center on Frame` it happens when `0.36 <= shutter`.

Evan Davies commented

2019-03-27 21:26:04 +01:00

Added subscriber: @EDcase

Added subscriber: @EDcase

Evan Davies commented

2019-03-27 21:26:04 +01:00

I seem to have the same issue with motion blur:
https://blender.stackexchange.com/questions/134545/extreme-motion-blur-for-particle-bullet-tracers

I seem to have the same issue with motion blur: https://blender.stackexchange.com/questions/134545/extreme-motion-blur-for-particle-bullet-tracers

Conrad Dueck commented

2019-04-12 00:05:27 +02:00

Added subscriber: @ConradDueck

Added subscriber: @ConradDueck

Brecht Van Lommel was unassigned by Dalai Felinto

2019-12-23 16:34:53 +01:00

Brecht Van Lommel commented

2020-01-27 13:11:58 +01:00

Owner

Changed status from 'Confirmed' to: 'Resolved'

Changed status from 'Confirmed' to: 'Resolved'

Brecht Van Lommel closed this issue

2020-01-27 13:11:58 +01:00

Brecht Van Lommel self-assigned this 2020-01-27 13:11:58 +01:00

Brecht Van Lommel commented

2020-01-27 13:11:58 +01:00

Owner

Fixed by e72ecaa.

Fixed by e72ecaa.

Sign in to join this conversation.

No Label

Animation & Rigging

Asset Browser Project Overview

Automated Testing

Blender Asset Bundle

Dependency Graph

Development Management

EEVEE & Viewport

Images & Movies

Motion Tracking

Nodes & Physics

Pipeline, Assets & IO

Platforms, Builds & Tests

Render & Cycles

Render Pipeline

Sculpt, Paint & Texture

Video Sequencer

Virtual Reality

Blender 2.8 Project

Milestone 1: Basic, Local Asset Browser

Good First Issue

Animation & Rigging

Development Management

EEVEE & Viewport

Nodes & Physics

Pipeline, Assets & IO

Platforms, Builds & Tests

Render & Cycles

Sculpt, Paint & Texture

Needs Info from Developers

Needs Information from User

No Milestone

No project

No Assignees

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#62655

No description provided.