Critical error when using motion blur

[JHåland]

Hi, I got this critical error message when using motion blur. Scene renders now as expected without motion blur.

28 times with:

[17:35:30] CRITICAL: Stop [ge_container.cpp(808)]

And then:

[17:35:33] CRITICAL: SymInitialize failed with GetLastError 87 [windows_crashhandler.cpp(507)]

Any idea why? I know there's not a lot to go on. But I use a couple of alembics in the scene, particles with TP Group, and a couple of Multi-Instances, and OIDN denoiser. I've tried to turn of and on a lot of different elements without luck, so the only thing that has made this go through is turning of motion blur.

[peter_horvath]

Is the application crashing, or do you have these error messages only in the console? Do you have this problem in the IPR or when rendering to the Picture Viewer? (I'm asking because motion blur in the IPR works a bit different than in final render.) Finally what's your Cinema 4D and C4DtoA version?

[JHåland]

Lots of great questions 🙂

I'm on r26,  the whole application crashes so this is for the debug log in the cinema 4d folder.

It renders 18 frames and stop at 19 no matter what.

Arnold 4.2.1, so not the latest version.

IPR has no problem showing the result.

[peter_horvath]

If you are on Windows, could you please check if you have a minidump.dmp in the HOME\AppData\Roaming\MAXON\Maxon Cinema 4D R26_XXXXXXXX\_bugreports folder? Check the date of the file if it's written after the crash. If so, please send it to me, maybe I can tell more from that file. It's possible the file is not written though, sometimes it's ignored after a hard crash.

---

---

Any change you can share the scene, maybe a simplified version? Just the minimum geos and materials/textures which still trigger the crash.

[JHåland]

Sorry for the late feedback. If I can send you the file directly I can share the project file.

But I quickly could create this .log

https://www.dropbox.com/s/19ihaq8hu2nsrx4/arnold.0055.log?dl=0

And here's a minidump

https://www.dropbox.com/s/ufeqp1tqll0utv6/minidump.dmp?dl=0

I see in log that there is some instances that create errors. But is this Arnold instance or c4d?

[peter_horvath · Accepted solution]

The first warning means, that deformation motion blur is enabled and there's a polymesh in the scene, called 'Polygon', which has different vertex/polygon count between frames. That's not supported and ignored.

The error about instances means that there's a Cloner probably, which generates different number of instances between frames, which is not supported.

Try setting the motion blur to 'start frame' instead of 'center frame' and change the length to make sure the keys are within the same frame.

https://docs.arnoldrenderer.com/display/A5AFCUG/Motion+Blur+-+settings

It should not crash though, so something's definitely wrong there. You can send the scene to support(at)arnoldrenderer(dot)com.

[JHåland]

I'm doing another project so haven't had time to test the scene.

"Start on frame" seem to do the trick, but I needed to reduce the motion blur keys from 16 to 8 too. "Center on frame" didn't work with 8. So i guess we have found the main problem here.

[thiago.ize]

16 keys will use 16 times more memory than a single key (no motion blur). Could it be you're running out of memory and that's why reducing the number of keys helps?

[JHåland]

Yes, could be. But it didn't help with center on frame. So not sure.

But 16 is way over what I needed for this, so being able to reduce it and also get the render done is a win win.

[Anonymous]

I'll add that switching from "center on frame" to "start on frame" also did help me, I got a scene with loads of XP trails that I wanted to motion blur, and IPR crashed half of the time, and render was just crashing 100% of the time. With start on frame, it works. (with the exact same error in the bug report file, so there seems to be some limitation with "center on frame" mode )

[JHåland]

ah nice to know, and strange that this is an occurring problem. 

[peter_horvath]

---

@Anonymous wrote:

I'll add that switching from "center on frame" to "start on frame" also did help me, I got a scene with loads of XP trails that I wanted to motion blur, and IPR crashed half of the time, and render was just crashing 100% of the time. With start on frame, it works. (with the exact same error in the bug report file, so there seems to be some limitation with "center on frame" mode )

---

Center frame mode can be tricky, because it requires moving back-and-forth on the timeline, however it should not crash. Would it be possible to share the scene with me to take a look?

[Anonymous]

Hi Peter ! thx a lot for your help, however right now I won't be able to export and send the scene, it's heavy as hell ( 2Go of mess) I've to clean in order to do so.

That said, I got pretty ok results with motion blur except for blurred transparency which became darker for some reason (probably got to increase depth, but the render just got 10x longer with motion blur already so that's not going to be possible in my current schedule) so I went another way, exporting motion vector pass in order to add blur during compositing, which works for now, the scene is fast and more graphical than realistic so cheaper blur technique will do the job here. 

However I don't know if it's possible to export camera motion blur into the motion vector pass ? right now I don't have it and didn't find out to do so.

[peter_horvath]

---

@Anonymous wrote:

However I don't know if it's possible to export camera motion blur into the motion vector pass ? right now I don't have it and didn't find out to do so.

---

It should be there by default. I made a quick test and both the motionvector AOV and the motion vector shader seemed to output the data correctly.

[Anonymous]

Hi Peter, again thanks for your help.

I'm having hard time understanding how does works motion vector and how to use them for example in After Effects with RSMB.

for example I've built a simple test scene with a camera going through a tunnel of cubes and a sphere in front of the camera that never move relativly to the camera (it's parented to the camera). so Basicly there is only camera blur on the cubes (which in fact is exported as you told, but I don't find how to use it properly) and the sphere should remain sharp/unblurred. 

Here is a capture of the scene :

the Base 3D

base 3D

first test with renderer motion blur settings 

motionvector* settings

motionvector* output

RSMB in After Effects result :

 

and another test with the shader method :

motion_vector shader settings :

result :

RSMB in AE result (better) :

results are differents, It seems the shader output is closer to what it should be, however it still behave weirdly, for instance, the still sphere at the center is always a bit blurred, and at the end of the animation, the camera slowly stops, nothing move anymore so here is the motion vector map generated by the shader method :

and applied to the render with RSMB

I found out that manipulating the levels of the blur map in AE to lighten the neutral vector color (the greenish yellow) help getting closer to removing blur when there is no movement, but there is still a bit of blur.

Is there something I didn't do well while preparing the motionvector map in Arnold ?