Eevee rendering with motion blur can change current frame #79213

New Issue

Paul R · 2020-07-24T02:18:06+02:00

Paul R commented

2020-07-24 02:18:06 +02:00

System Information
Operating system: SUSE Leap 15.1
Graphics card: NVidia RTX 2070 Super (official drivers)

Blender Version
Broken: 2.90, 9cbf43801b, x86_64 linux, 2020-07-23
Worked: 2.90, aed11c673e, x86_64 linux, 2020-06-06

Short description of error
With the motion blur shutter value set above 2.00 and a high steps value (eg 32), the current scene frame will shift forwards with each f12 render. Higher shutter and steps values will cause progressively larger jumps forwards.

Exact steps for others to reproduce the error

set Eevee renderer
enable motion blur
set a shutter value of 4.0
set a steps value of 32

#79213.blend

F12 render

Current frame will advance by +1

Although it's unusual for a shutter to go above 1.0 seconds in most situations, some digital cameras and frame-stores can do this for artistic effect so it'd be a shame to be limited it to 1 second or less. Even old tube cameras could do it around bright lights because of phosphor decay!

Edit: This coincides with the recent changes to motion blur. I have amended the Broken/Working details.

**System Information** Operating system: SUSE Leap 15.1 Graphics card: NVidia RTX 2070 Super (official drivers) **Blender Version** Broken: 2.90, 9cbf43801ba2, x86_64 linux, 2020-07-23 Worked: 2.90, aed11c673efe, x86_64 linux, 2020-06-06 **Short description of error** With the motion blur shutter value set above 2.00 and a high steps value (eg 32), the current scene frame will shift forwards with each f12 render. Higher shutter and steps values will cause progressively larger jumps forwards. **Exact steps for others to reproduce the error** - set Eevee renderer - enable motion blur - set a shutter value of 4.0 - set a steps value of 32 [#79213.blend](https://archive.blender.org/developer/F8723365/T79213.blend) - F12 render Current frame will advance by +1 Although it's unusual for a shutter to go above 1.0 seconds in most situations, some digital cameras and frame-stores can do this for artistic effect so it'd be a shame to be limited it to 1 second or less. Even old tube cameras could do it around bright lights because of phosphor decay! **Edit:** This coincides with the recent changes to motion blur. I have amended the Broken/Working details.

blender-admin commented

2020-07-24 02:18:06 +02:00

#79430 was marked as duplicate of this issue

Paul R commented

2020-07-24 02:18:07 +02:00

Added subscriber: @intracube

Germano Cavalcante commented

2020-07-24 22:44:45 +02:00

Added subscriber: @mano-wii

Germano Cavalcante commented

2020-07-24 22:44:45 +02:00

I'm not sure if I understand the problem, should I create an animation first?
Could you submit a simple file demonstrating the problem?

I'm not sure if I understand the problem, should I create an animation first? Could you submit a simple file demonstrating the problem?

Paul R commented

2020-07-25 17:40:06 +02:00

This should happen with the default scene with only those few settings changed. After pressing F12 a few times, this is the result:

The global frame has shifted from 1 to 4.

This should happen with the default scene with only those few settings changed. After pressing F12 a few times, this is the result: ![T79213_eevee_motion_blur_causes_global_frame_shift_v2.png](https://archive.blender.org/developer/F8719972/T79213_eevee_motion_blur_causes_global_frame_shift_v2.png) The global frame has shifted from 1 to 4.

YAFU commented

2020-07-25 18:04:14 +02:00

Added subscriber: @YAFU

YAFU commented

2020-07-25 18:04:14 +02:00

I can confirm it, incrementally by one frame in each F12 render.

Richard Antalik changed title from ~~Eevee motion blur can cause the scene frame to shift forwards.~~ to Eevee rendering with motion blur can change current frame

2020-07-27 17:31:54 +02:00

Richard Antalik commented

2020-07-27 17:31:54 +02:00

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