Weird motion blur occuring when using drivers #73236

New Issue

Jindřich Olšar · 2020-01-19T10:27:47+01:00

Jindřich Olšar commented

2020-01-19 10:27:47 +01:00

mblur_drivers.blend
Operating system: Windows 10 64bit
Graphics card: Nvidia 1060 6gb

Broken: 2.81

Objects driven by drivers have weird motion blur. In 60 frame animation (24fps) the motion blur "resetted" twice, 2nd just before the end so it could be every second (24 frames)

Animate object going from on position to other. Set the driver for rotation axis of your choice so the objects rotates as it moves (I've used this for rolling wheel). Enable motion blur (default settings in my case) and render animation. When rendering single frames nothing happened (occured when rendering animation on .png and .avi jpeg). I have rendered 3 scenarios, 1st is my case, moving object and his rotation driven by driver (motion blur is wrong), 2nd is position and rotation manually keyframed, no drivers used, just keyframes (mblur worked), 3rd is case is, which I hoped would work, emptys location being animated, rotation driven by driver. Object then parented onto the empty. Didn't work. Rendering on CPU didn't help also.

[mblur_drivers.blend](https://archive.blender.org/developer/F8287209/mblur_drivers.blend) *Operating system*: Windows 10 64bit *Graphics card*: Nvidia 1060 6gb *Broken*: 2.81 Objects driven by drivers have weird motion blur. In 60 frame animation (24fps) the motion blur "resetted" twice, 2nd just before the end so it could be every second (24 frames) Animate object going from on position to other. Set the driver for rotation axis of your choice so the objects rotates as it moves (I've used this for rolling wheel). Enable motion blur (default settings in my case) and render animation. When rendering single frames nothing happened (occured when rendering animation on .png and .avi jpeg). I have rendered 3 scenarios, 1st is my case, moving object and his rotation driven by driver (motion blur is wrong), 2nd is position and rotation manually keyframed, no drivers used, just keyframes (mblur worked), 3rd is case is, which I hoped would work, emptys location being animated, rotation driven by driver. Object then parented onto the empty. Didn't work. Rendering on CPU didn't help also. 1) https://www.youtube.com/watch?v=XKMTGqFQte8 2) https://www.youtube.com/watch?v=e2cbqpYZN90 3) https://www.youtube.com/watch?v=CSwcuDPjw1s

Jindřich Olšar commented

2020-01-19 10:27:47 +01:00

Added subscriber: @olsarxd

Evan Wilson commented

2020-01-19 20:49:12 +01:00

Added subscriber: @EAW

Evan Wilson commented

2020-01-19 20:49:12 +01:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Evan Wilson commented

2020-01-19 20:49:12 +01:00

Thank you for the report.

You seem to have uploaded the wrong file, instead of the one shown in your videos. The file appears to be from 2.79 with a broken driver. I fixed the driver and rendered it out using both 2.81 and today's 2.83 build. They are identical and the motion blur behaves as expected as far as I can see.

bim_0001-0060.mp4

Without the correct file, I am not sure what more can be done.

Could you please upload it?

There was a bug with cycles motion blur that has been fixed in the daily builds. Perhaps this is the issue you are experiencing?

Please download a daily build from below and see if your issue has been fixed.

https://builder.blender.org/download/

Thank you for the report. You seem to have uploaded the wrong file, instead of the one shown in your videos. The file appears to be from 2.79 with a broken driver. I fixed the driver and rendered it out using both 2.81 and today's 2.83 build. They are identical and the motion blur behaves as expected as far as I can see. [bim_0001-0060.mp4](https://archive.blender.org/developer/F8288303/bim_0001-0060.mp4) Without the correct file, I am not sure what more can be done. Could you please upload it? There was a bug with cycles motion blur that has been fixed in the daily builds. Perhaps this is the issue you are experiencing? Please download a daily build from below and see if your issue has been fixed. https://builder.blender.org/download/

Evan Wilson commented

2020-01-26 18:01:57 +01:00

In F8288303 #463, @olsarxd wrote:
No way, I'm 100% sure I've used 2.81, the splash screen said 2.81 and I recreated the scene using that version. I'll download 2.83a and try it again.

I've downloaded the new 2.83a, it had the space themed splash screen. I'll upload the file, I did the same thing, set the X rotation to a driver, the driver to "get data from Y location of the cube", animate position on frame 1 and 60, set the interpolation to linear. Enable motion blur, default settings, cycles, render of GPU, hit ctrl + F12 and it did the same thing again.

Your animation seems to be only animated using keyframes, not sure where and how did you use the drivers. The motion blur is also correct when I just spin the cube, the problem occurs when using the drivers.
0001-0060.avi
mblur_drivers2.blend

I would love to fix the issue since my project requires a lot of driver animation.

Thank you for uploading the file, now we can be sure that we are talking about the same thing. =)

I can confirm that I get the same motion blur issue when I render your file.

0001-0060.mp4

However, if I add an empty and keyframe it's location, and use that to drive the cube's rotation, the motion blur is fine. The cube's location is still also keyframed.

Empty_y_loc_as_cube_x_rotation0001-0060.mp4

Deleting the cube's location keyframes, and using the empty's location as the cube's location and rotation driver, the motion blur is fine.

Empty_loc_as_cube_rot_and_loc0001-0060.mp4

Deleting the cube's location driver's, and parenting the cube to the empty, the motion blur is fine.

Empty_loc_as_cube_rot_cube_parented0001-0060.mp4

This last case appears identical to what your wrote as your third case, so I don't know why it didn't work for you, since that case wasn't included in your file.

If I take your original cube and change the driver type from transform to single property, opening the console window will show

OBCube_driver_single_property/Transform Component/TRANSFORM_INIT() depends on
OBCube_driver_single_property/Parameters Component/DRIVER(rotation_euler) via 'Driver -> Driven Property'
OBCube_driver_single_property/Transform Component/TRANSFORM_FINAL() via 'RNA Target -> Driver'
OBCube_driver_single_property/Transform Component/TRANSFORM_SIMULATION_INIT() via 'Simulation -> Final Transform'
OBCube_driver_single_property/Transform Component/TRANSFORM_EVAL() via 'Transform Eval -> Simulation Init'
OBCube_driver_single_property/Transform Component/TRANSFORM_LOCAL() via 'Eval'
OBCube_driver_single_property/Transform Component/TRANSFORM_INIT() via 'Transform Init'

Detected 1 dependency cycles```


This is a dependency cycle issue.  See https://developer.blender.org/T69101#842779 for more information.

Closing this as a duplicate of #64793

Here is your second file with my 4 additional test cases included.



[mblur_drivers2_EAW_version.blend](https://archive.blender.org/developer/F8303221/mblur_drivers2_EAW_version.blend)





---

Side note:

I trust that you created the report's first videos using 2.8x, it was just the first file that you uploaded was made using 2.69, as seen in outliner in the screenshot below.

![2.69.jpg](https://archive.blender.org/developer/F8303064/2.69.jpg)

Here is the file that I used to make the video in my post above, in which I changed the driver of the cube's z-rotation to use the empty's z-location, in case you were curious.

[mblur_drivers_EAW_fixed_version.blend](https://archive.blender.org/developer/F8303070/mblur_drivers_EAW_fixed_version.blend)

> In [F8288303](https://archive.blender.org/developer/F8288303/bim_0001-0060.mp4)#463, @olsarxd wrote: > No way, I'm 100% sure I've used 2.81, the splash screen said 2.81 and I recreated the scene using that version. I'll download 2.83a and try it again. > > I've downloaded the new 2.83a, it had the space themed splash screen. I'll upload the file, I did the same thing, set the X rotation to a driver, the driver to "get data from Y location of the cube", animate position on frame 1 and 60, set the interpolation to linear. Enable motion blur, default settings, cycles, render of GPU, hit ctrl + F12 and it did the same thing again. > > Your animation seems to be only animated using keyframes, not sure where and how did you use the drivers. The motion blur is also correct when I just spin the cube, the problem occurs when using the drivers. > [0001-0060.avi](https://archive.blender.org/developer/F8299593/0001-0060.avi) > [mblur_drivers2.blend](https://archive.blender.org/developer/F8299594/mblur_drivers2.blend) > > I would love to fix the issue since my project requires a lot of driver animation. Thank you for uploading the file, now we can be sure that we are talking about the same thing. =) I can confirm that I get the same motion blur issue when I render your file. [0001-0060.mp4](https://archive.blender.org/developer/F8303082/0001-0060.mp4) However, if I add an empty and keyframe it's location, and use that to drive the cube's rotation, the motion blur is fine. The cube's location is still also keyframed. [Empty_y_loc_as_cube_x_rotation0001-0060.mp4](https://archive.blender.org/developer/F8303202/Empty_y_loc_as_cube_x_rotation0001-0060.mp4) Deleting the cube's location keyframes, and using the empty's location as the cube's location and rotation driver, the motion blur is fine. [Empty_loc_as_cube_rot_and_loc0001-0060.mp4](https://archive.blender.org/developer/F8303206/Empty_loc_as_cube_rot_and_loc0001-0060.mp4) Deleting the cube's location driver's, and parenting the cube to the empty, the motion blur is fine. [Empty_loc_as_cube_rot_cube_parented0001-0060.mp4](https://archive.blender.org/developer/F8303210/Empty_loc_as_cube_rot_cube_parented0001-0060.mp4) This last case appears identical to what your wrote as your third case, so I don't know why it didn't work for you, since that case wasn't included in your file. If I take your original cube and change the driver type from `transform` to `single property`, opening the console window will show ```Dependency cycle detected: ``` OBCube_driver_single_property/Transform Component/TRANSFORM_INIT() depends on OBCube_driver_single_property/Parameters Component/DRIVER(rotation_euler) via 'Driver -> Driven Property' OBCube_driver_single_property/Transform Component/TRANSFORM_FINAL() via 'RNA Target -> Driver' OBCube_driver_single_property/Transform Component/TRANSFORM_SIMULATION_INIT() via 'Simulation -> Final Transform' OBCube_driver_single_property/Transform Component/TRANSFORM_EVAL() via 'Transform Eval -> Simulation Init' OBCube_driver_single_property/Transform Component/TRANSFORM_LOCAL() via 'Eval' OBCube_driver_single_property/Transform Component/TRANSFORM_INIT() via 'Transform Init' ``` Detected 1 dependency cycles``` This is a dependency cycle issue. See https://developer.blender.org/T69101#842779 for more information. Closing this as a duplicate of #64793 Here is your second file with my 4 additional test cases included. [mblur_drivers2_EAW_version.blend](https://archive.blender.org/developer/F8303221/mblur_drivers2_EAW_version.blend) --- Side note: I trust that you created the report's first videos using 2.8x, it was just the first file that you uploaded was made using 2.69, as seen in outliner in the screenshot below. ![2.69.jpg](https://archive.blender.org/developer/F8303064/2.69.jpg) Here is the file that I used to make the video in my post above, in which I changed the driver of the cube's z-rotation to use the empty's z-location, in case you were curious. [mblur_drivers_EAW_fixed_version.blend](https://archive.blender.org/developer/F8303070/mblur_drivers_EAW_fixed_version.blend)

Evan Wilson commented

2020-01-26 18:02:14 +01:00

Closed as duplicate of #64793

Evan Wilson closed this issue

2020-01-26 18:02:14 +01:00

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Weird motion blur occuring when using drivers #73236