Cycles Motion Blur takes exponential time to render with GPU #41644

New Issue

thomas lebrun · 2014-08-30T15:11:38+02:00

thomas lebrun commented

2014-08-30 15:11:38 +02:00

System Information
Windows 7 64bits, GTX 780

Blender Version
Broken: 2.71 9337574
Worked: 2.70

When rendering images with cycles, motion blur activated and GPU, render time grows infinitly ( till windows crashes more precisely...) for each image (for example : first image 1s, second image 2s, etc...)
Before the rendering of every image, there is a time when nothing happens, and this time is longer at each image.

I monitored my Card, temperature and memory are stable and maximum is not reached.

I tested with CPU, no problem. I tested on 2.70, no problem.

Exact steps for others to reproduce the error

Open file
ctrl F12
around the 15th image, render time starts to be really big
test_motion_blur_gpu.blend1

**System Information** Windows 7 64bits, GTX 780 **Blender Version** Broken: 2.71 9337574 Worked: 2.70 When rendering images with cycles, motion blur activated and GPU, render time grows infinitly ( till windows crashes more precisely...) for each image (for example : first image 1s, second image 2s, etc...) Before the rendering of every image, there is a time when nothing happens, and this time is longer at each image. I monitored my Card, temperature and memory are stable and maximum is not reached. I tested with CPU, no problem. I tested on 2.70, no problem. **Exact steps for others to reproduce the error** - Open file - ctrl F12 - around the 15th image, render time starts to be really big [test_motion_blur_gpu.blend1](https://archive.blender.org/developer/F107461/test_motion_blur_gpu.blend1)

thomas lebrun commented

2014-08-30 15:11:38 +02:00

Changed status to: 'Open'

thomas lebrun commented

2014-08-30 15:11:38 +02:00

Added subscriber: @ThomasLebrun

Sergey Sharybin was assigned by Bastien Montagne

2014-08-30 16:46:45 +02:00

Bastien Montagne commented

2014-08-30 16:46:45 +02:00

Added subscriber: @mont29

Bastien Montagne commented

2014-08-30 16:46:45 +02:00

Sergey, this is your playground :)

Bastien Montagne commented

2014-08-30 16:47:23 +02:00

Added subscribers: @ThomasDinges, @MartijnBerger

Bastien Montagne commented

2014-08-30 16:47:23 +02:00

Yet, Thomas and Martijn might want to have a look too!

Sergey Sharybin commented

2014-09-01 15:05:17 +02:00

Does this happen with both rendering to a movie and image sequence?

thomas lebrun commented

2014-09-01 19:03:00 +02:00

I just tried, bugs in both cases.
Even with rendering single images from time to time, it bugs.

I just tried, bugs in both cases. Even with rendering single images from time to time, it bugs.

Sergey Sharybin commented

2014-09-01 20:41:36 +02:00

Wasn't able to reproduce so far, but mainly tried on linux and it might be platform-specific, will give another attempt on windows tomorrow..

Another question is: what if you open the file, jump straight to frame 15 and render single image? Would it be normal time or some real slow time to render?

And what if you'll start rendering frame by frame in a way like F12, go to next frame, F1 go to the next frame and so?

Wasn't able to reproduce so far, but mainly tried on linux and it might be platform-specific, will give another attempt on windows tomorrow.. Another question is: what if you open the file, jump straight to frame 15 and render single image? Would it be normal time or some real slow time to render? And what if you'll start rendering frame by frame in a way like F12, go to next frame, F1 go to the next frame and so?

thomas lebrun commented

2014-09-01 21:39:24 +02:00

It is like there is a cache, filling progressively at each render, if i render 15 times the first image with F12 i'll have the same result... Only way to empty this cache is to restart blender...

thomas lebrun commented

2014-09-01 21:49:24 +02:00

just in case, here is a video of the bug so you see the problem clearly : http://youtu.be/btCUrvmeJrg

Sergey Sharybin commented

2014-09-04 17:41:56 +02:00

Can not reproduce the issue so far, also it's seems that time is spent on the rame update, not on the actual rendering.

Please try the following:

Try using latest blender from builder.blender.org
Loading factory startup before rendering, so no extra addons are loaded (ideally is to load factory startup, save it and restart blender, you might want to backup your config first)

Can not reproduce the issue so far, also it's seems that time is spent on the rame update, not on the actual rendering. Please try the following: - Try using latest blender from builder.blender.org - Loading factory startup before rendering, so no extra addons are loaded (ideally is to load factory startup, save it and restart blender, you might want to backup your config first)

thomas lebrun commented

2014-09-08 18:57:55 +02:00

It was the valve source addon.
If i don't activate it i have no problem.

Sorry for wasting your time with a none core blender related problem.

Thanks for your advices.

It was the valve source addon. If i don't activate it i have no problem. Sorry for wasting your time with a none core blender related problem. Thanks for your advices.

Sergey Sharybin commented

2014-09-08 19:02:34 +02:00

Changed status from 'Open' to: 'Resolved'

Sergey Sharybin closed this issue

2014-09-08 19:02:34 +02:00

Sergey Sharybin commented

2014-09-08 19:02:34 +02:00

No worries! Closing the report as resolved then!

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Cycles Motion Blur takes exponential time to render with GPU #41644