motion blur: performance degradation in 2.71 #41512

New Issue

Sergey Sharybin · 2014-08-20T18:51:56+02:00

ag commented

2014-08-20 18:51:56 +02:00

(Migrated from localhost:3001)

System Information
Debian GNU/Linux Jessie (testing)
AMD Phenom II X4 850

Blender Version
Broken: 2.71
Worked: 2.70a2

Short description of error
I observe extremely slow rendering using particle system and activated motion blur.

Exact steps for others to reproduce the error
You can try - [x]. Switch to cycles render, enable Motion Blur. Go to frame 103. Render.

Thanks,
Andrey

P.S. - [x] is originating from - [x]. I believe it is inspired by - [x], but BlenderDiplom's version is not cycles ready.

**System Information** Debian GNU/Linux Jessie (testing) AMD Phenom II X4 850 **Blender Version** Broken: 2.71 Worked: 2.70a2 **Short description of error** I observe extremely slow rendering using particle system and activated motion blur. **Exact steps for others to reproduce the error** You can try - [x]. Switch to cycles render, enable Motion Blur. Go to frame 103. Render. Thanks, Andrey P.S. - [x] is originating from - [x]. I believe it is inspired by - [x], but BlenderDiplom's version is not cycles ready. - [x] https://www.dropbox.com/s/toy8iwfp1gyr51e/Logo%20reloaded.blend - [x] http://www.youtube.com/watch?v=FB4SZCTIcuo - [x] http://blenderdiplom.com/en/tutorials/394-tutorial-dissolve-your-logo-in-blender-262.html

ag commented

2014-08-20 18:51:56 +02:00

(Migrated from localhost:3001)

Changed status to: 'Open'

ag commented

2014-08-20 18:51:56 +02:00

(Migrated from localhost:3001)

Added subscriber: @ag

Sergey Sharybin was assigned by Bastien Montagne

2014-08-20 19:08:20 +02:00

aaronmc commented

2014-08-20 19:14:11 +02:00

(Migrated from localhost:3001)

Added subscriber: @aaronmc

aaronmc commented

2014-08-20 19:14:11 +02:00

(Migrated from localhost:3001)

I'm encountering a similar issue. A scene with sugar packets exploding from a bin causes renders to more-or-less stop.

Roman Volodin commented

2014-08-20 23:06:38 +02:00

Added subscriber: @cronk

Roman Volodin commented

2014-08-20 23:11:16 +02:00

I can confirm the regression. I did a test (no particles just animated object with huge motion blur) and 2.70a is about 7-8 times faster than 2.71
Oh man, I thought I was wrong =|

I can confirm the regression. I did a test (no particles just animated object with huge motion blur) and 2.70a is about 7-8 times faster than 2.71 Oh man, I thought I was wrong =|

Thomas Dinges commented

2014-08-20 23:49:16 +02:00

Added subscriber: @ThomasDinges

Thomas Dinges commented

2014-08-20 23:49:16 +02:00

I don' think this is a bug.

In 2.71, Deformation Motion Blur was added. Disable the "Deformation" checkbox in the Object Tab -> Motion Blur panel and the image renders in a few seconds.

I don' think this is a bug. In 2.71, Deformation Motion Blur was added. Disable the "Deformation" checkbox in the Object Tab -> Motion Blur panel and the image renders in a few seconds.

Thomas Dinges commented

2014-08-20 23:49:51 +02:00

Changed status from 'Open' to: 'Archived'

Thomas Dinges closed this issue

2014-08-20 23:49:51 +02:00

ag commented

2014-08-21 18:56:05 +02:00

(Migrated from localhost:3001)

@ThomasDinges: thanks for clarifying. But what considerations has been taken into account to make this "deformation" option enabled per default?
Considering my configuration: blender renders the frame in 2-3 seconds or with motion blur estimated time is 1 hour 44 minutes. The factor 2000 is extremely huge.

@ThomasDinges: thanks for clarifying. But what considerations has been taken into account to make this "deformation" option enabled per default? Considering my configuration: blender renders the frame in 2-3 seconds or with motion blur estimated time is 1 hour 44 minutes. The factor 2000 is extremely huge.

Thomas Dinges commented

2014-08-21 19:57:36 +02:00

As every new feature, it is enabled per default, it's not really possible to have backward compatibility here. It's also noted in our release logs that this is enabled per default: http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.71/Cycles

ag commented

2014-08-25 16:27:49 +02:00

(Migrated from localhost:3001)

As every new feature, it is enabled per default

When I start Blender, the new "Cycles render" is not enabled. But if I open an old blend-file, a new "freestyle" feature is enabled, which is not an improvement of an existed one, but something totally different. So the Blender's policy to enable improvements also apply to enabling such foreign things?

Thinking, why I haven't noticed the deformation option myself, I came up with following observation. I've enabled this feature in the "render" tab. And there are no such option like "deformation". Why is it missing there? It's somewhat ambiguous, when something got hidden enabled.

For what use cases the "deformation" option has been tested? Maybe the solution would be just to have default disable for objects with particle systems? Or at least clear warning about performance degradation leading to unusable state either enabling motion blur for objects with particle systems or adding a particle system to object with deformation motion blur?

> As every new feature, it is enabled per default When I start Blender, the new "Cycles render" is not enabled. But if I open an old blend-file, a new "freestyle" feature is enabled, which is not an improvement of an existed one, but something totally different. So the Blender's policy to enable improvements also apply to enabling such foreign things? Thinking, why I haven't noticed the deformation option myself, I came up with following observation. I've enabled this feature in the "render" tab. And there are no such option like "deformation". Why is it missing there? It's somewhat ambiguous, when something got hidden enabled. For what use cases the "deformation" option has been tested? Maybe the solution would be just to have default disable for objects with particle systems? Or at least clear warning about performance degradation leading to unusable state either enabling motion blur for objects with particle systems or adding a particle system to object with deformation motion blur?

Thomas Dinges commented

2014-08-25 17:05:18 +02:00

The Deformation option is inside the Object Tab, because you can disable Deformation Motion Blur on a per object basis. The loss of backward compatibility is unfortunate here, but Motion Blur = Camera, Object and Deformation. Like Ray Visibility or other things, the user has to disable it, if he does not want it.

Cycles aims to be physically accurate per default, that includes all motion blur effects.

The Deformation option is inside the Object Tab, because you can disable Deformation Motion Blur on a per object basis. The loss of backward compatibility is unfortunate here, but Motion Blur = Camera, Object and Deformation. Like Ray Visibility or other things, the user has to disable it, if he does not want it. Cycles aims to be physically accurate per default, that includes *all* motion blur effects.

ag commented

2014-08-25 17:19:54 +02:00

(Migrated from localhost:3001)

because you can disable Deformation Motion Blur on a per object basis

But it is consequent to be able to disable all deformations at once, just like I can disable motion blur at once (on the "render" tab). Or not?

You haven't mentioned the freestyle issue, should I open a new bug or it is better to rise the issue in a developer mailing list (is there one)?

In meanwhile I figured out the actual trigger of the drastic performance drop. Is it possible to reopen and retitle this bug or should I open a new one?

> because you can disable Deformation Motion Blur on a per object basis But it is consequent to be able to disable all deformations at once, just like I can disable motion blur at once (on the "render" tab). Or not? You haven't mentioned the freestyle issue, should I open a new bug or it is better to rise the issue in a developer mailing list (is there one)? In meanwhile I figured out the actual trigger of the drastic performance drop. Is it possible to reopen and retitle this bug or should I open a new one?

Thomas Dinges commented

2014-08-25 17:26:52 +02:00

Please don't mix issues in one report, open a new one.

You cannot disable Deformations for all objects with 1 button. You can also not disable all Subsurface Shaders or make all objects invisible for Camera rays at once. That can be done with a 2 line Python script if you need it. We maybe can add such Global De activators once, but that is a Feature Request / Improvement then, not a bug.

Please don't mix issues in one report, open a new one. You cannot disable Deformations for all objects with 1 button. You can also not disable all Subsurface Shaders or make all objects invisible for Camera rays at once. That can be done with a 2 line Python script if you need it. We maybe can add such Global De activators once, but that is a Feature Request / Improvement then, not a bug.

ag commented

2014-08-25 17:56:46 +02:00

(Migrated from localhost:3001)

but that is a Feature Request / Improvement then, not a bug.

Where can be such issues posted?

>but that is a Feature Request / Improvement then, not a bug. Where can be such issues posted?

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motion blur: performance degradation in 2.71 #41512