Boolean - Animation - Viewport works correctly render view doesnt
Open, ConfirmedPublic

Description

System Information
Ubuntu 18.04, Win 7 x64

Blender Version
Broken: d53093953f8

Short description of error
Booleans dont match between Viewport and Render

Exact steps for others to reproduce the error

  1. Open attached blend file
  2. Preview render (shift z)
  3. Notice the green on top
  4. F12 Render
  5. Notice how the green is no longer there

Details

Type
Bug

Seems like it has something to do with the animation on the Boolean. Clearing the animation makes the boolean work correctly.

It has to do with cycles motion blur, 2.79b seems to render fine.
Disabeling motion blur or setting it to Center on Frame seems to render the boolean OK.

Philipp Oeser (lichtwerk) triaged this task as Confirmed priority.

Sorry about the regression tag, 2.79b with bmesh boolean was also bad...
So, seems to be limitation with bmesh booleans not supporting cycles motion blur in certain scenarios... (e..g. frame 462 in example file is bad, 461 is good, 463 also is...)

Confirming, digging deeper later... maybe @Brecht Van Lommel (brecht) knows right away?

Brecht Van Lommel (brecht) claimed this task.

It's a documented limitation, animated booleans don't work well with motion blur.
https://docs.blender.org/manual/en/dev/render/cycles/settings/scene/render/motion_blur.html

The only solution for now is to disable motion blur for such objects.

Carlo Andreacchio (candreacchio) raised the priority of this task from Confirmed to Needs Triage.Jun 30 2018, 3:33 AM

@Brecht Van Lommel (brecht) disabling the motion blur for both objects does not fix the issue. I have reuploaded the file, with both objects having disabled motionblur yet the bug persists

Bastien Montagne (mont29) triaged this task as Confirmed priority.Jul 23 2018, 8:49 PM

Can confirm that even though mblur is disabled for both operand objects, result in render is wrong. You have to disable mblur for whole Cycles (in its render settings) to get correct render.