Render Errors with Motion Blur

[JonasNöll]

Hi,

I have a fairly complicated scene with lots of highpoly geometry. Most converted to V-Ray Proxy though.
It renders without issues when motion blur is turend off, but when enable motionblur it randomly stops rendering after sometimes a few frames, sometimes after one frame. If then resubmit the same frame it sometimes renders and sometimes not. It seems really random.

3ds Max Physical Camera Motionblur is set to 0.5, offset -0,25.
I am using the progressive Renderer.

Error Messages from the log are those:
- Error : Building Embree Voxel Tree failed: [EmbreeTree<0,1,class VUtils::StaticTreeDelegateParam,struct VUtils::SimpleStaticTriangle,struct VUtils::SDTreeBunchDelegetorFace>::build] 1: Creating new scene failed
- Error : Error building Embree static ray caster, error message: [CommitEmbreeThread::threadProc] 1: Setting progress monitor function failed

Is there anything that I can try?

[Morbid Angel]

Are you running out of ram?

[JonasNöll]

According to Windows Task Manager I still have around 20GB available out of my 64GB during rendering.
It always renders the first image of the sequence I submit and then crahses.
So I submit 1-10 it will render 1, then crash. Then I submit 2-10 it will render 2, then crash. Then submit 3-10, it will render 3, then crash. And so on.
No issues in IPR, also with MotionBlur enabled...

[Morbid Angel]

It could be related to the progressive rendering. Can you switch to bucket and see if it makes any difference. Progressive is intense on resources as it loads everything at once.

[JonasNöll]

Yeah I tried that but unfortunately same result. Also tried the conserve memory option in the render settings.

[JonasNöll]

This is the memory graph. First frame of the submitted sequence renders always fine (no matter which frame is the first one). It shouldn't be a memory issue then or?

[kosso_olli]

To me this seems like a memory issue pretty much. Especially the progressive sampler will consume lots of RAM, even more when using many render elements.

[JonasNöll]

Ok, it seems it really was a memory issue. it seems fixed now.
I converted all the remaining geometry also to VRayProxies and that seemed to have fixed it. Before I just had all the instanced highpoly geometry as proxies. It reduces the memory consumption by roughly another 30% and so far I haven't had any crashes for around 20 rendered frames now.
The power of proxies
Thx for the help! The idea with the renderelements is also good, wouldn't have thought about that.

[^Lele^]

On the use of Bucket or Progressive sampler.
On V-Ray and Memory and Speed savings.
Both are officially sanctioned guides, and still very valid.

[JonasNöll]

Great ressources, thx!