Maniphest T70694

Cycles : Motion blur bug
Closed, Resolved
Actions

Assigned To
Brecht Van Lommel (brecht)
Authored By
Lucas Boutrot (thornydre)
Oct 10 2019, 11:18 AM
Tags
  • BF Blender
  • Cycles
  • Tracker Curfew
Subscribers
Andrew Charlton (Scaredyfish)
Brecht Van Lommel (brecht)
Germano Cavalcante (mano-wii)
Giacomo Balma (iamlab)
Lucas Boutrot (thornydre)
Mateusz Mielnicki (mielnicki)
Tokens
"The World Burns" token, awarded by iamlab.

Description

System Information
Operating system: Windows-10-10.0.18362 64 Bits
Graphics card: GeForce GTX 1060/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 436.48

Blender Version
Broken: version: 2.81 (sub 14), branch: master, commit date: 2019-10-09 18:33, hash: rBe84685286274

Short description of error

On the frame 13 I have a really strong motion blur, but the speed of my camera or my object isn’t changing that much. If I offset the entire animation of the camera even slightly, it disappears.

If I turn the motion blur off, it disappears as well.

Changing the animation of the card does not change anything.

Exact steps for others to reproduce the error

cycles_bug.blend29 MBDownload

  • Open the file
  • Render frame 13

Revisions and Commits

rB Blender
ClosedD6537 Fix T66529: [Cycles] Motion Blur of fast rotating objects "randomly" glitches

Related Objects

Event Timeline

Lucas Boutrot (thornydre) created this task.Oct 10 2019, 11:18 AM
Philipp Oeser (lichtwerk) added a project: Cycles.Oct 10 2019, 11:23 AM
Andrew Charlton (Scaredyfish) added a subscriber: Andrew Charlton (Scaredyfish).Oct 11 2019, 1:30 AM

I get the same result. Here's a less noisy version.

Germano Cavalcante (mano-wii) assigned this task to Brecht Van Lommel (brecht).Oct 14 2019, 2:50 PM
Germano Cavalcante (mano-wii) lowered the priority of this task from 90 to 50.
Germano Cavalcante (mano-wii) added a subscriber: Germano Cavalcante (mano-wii).

I can replicate, but I'm not sure if the problem is in the file or in Cycles.

Giacomo Balma (iamlab) added a subscriber: Giacomo Balma (iamlab).Oct 14 2019, 11:19 PM

May be related to T66529

Giacomo Balma (iamlab) awarded a token.Oct 14 2019, 11:19 PM
Giacomo Balma (iamlab) rescinded a token.
Giacomo Balma (iamlab) awarded a token.
Mateusz Mielnicki (mielnicki) added a subscriber: Mateusz Mielnicki (mielnicki).Nov 6 2019, 4:08 PM

I can confirm that its happening from time to time in 2.8 stable.
Cant be file fault, I have cleaned everything up trying to debug it...
It seams to look close to artifacts with T66529
Maybe some precision error? while computing velocity... also alpha channel sems to be much more blurried in this frames.

Mateusz Mielnicki (mielnicki) added a comment.Nov 6 2019, 4:11 PM

Here is my file, same error but without spinning, only camera movement.
Frame 122 is different than others in all animation.

{F7961729}
Dalai Felinto (dfelinto) removed Brecht Van Lommel (brecht) as the assignee of this task.Dec 23 2019, 1:47 PM
Dalai Felinto (dfelinto) added a project: Tracker Curfew.
Dalai Felinto (dfelinto) added a subscriber: Brecht Van Lommel (brecht).
Josh Belanich (jbelanich) added a revision: D6537: Fix T66529: [Cycles] Motion Blur of fast rotating objects "randomly" glitches.Jan 7 2020, 4:28 AM
Lucas Boutrot (thornydre) mentioned this in T66529: [Cycles] Motion Blur of fast rotating objects "randomly" glitches.Jan 8 2020, 5:40 PM
Brecht Van Lommel (brecht) closed this task as Resolved.Jan 8 2020, 5:47 PM
Brecht Van Lommel (brecht) claimed this task.

Resolved along with T66529 according to comment there.