Motion Blur issue on high poly, rigged model

[jameskowalski]

Hi all, I'm experiencing a weird issue with motion blur not behaving consistently from frame to frame.

I have a rigged advanced biped model that has an octane objectTag applied to a null containing all my model's mesh and character controls. Transform/vertex is selected from the object motion blur dropdown. My camera's motion blur option is enabled with a shutter speed of .03. Time shift : 0, and M.blur cache frames : 25.

The weird thing is that for the first 5 or so frames of the animation, motion blur is only applied to parts of the model, then 5 frames in it becomes apparent as it should.

Any ideas as to what could be causing this? I'm fresh out of ideas.

[aoktar]

Can't you attach the image in to topic? I cannot see that.

[jameskowalski]

Sure, thanks for looking.

[aoktar]

Do you have object tag which is affecting whole model?
Does your models have constant topology?
What do you see in Console window? Any error messages about motion blur?

[jameskowalski]

No errors when rendering in LV or PV, and yes the tag is applied to the whole mesh, or at least it's applied to the mesh's parent null, which should work, correct? The model doesn't change its topology over the coarse of the animation either.

After doing a BUNCH of testing, I think the problem is somehow tied to the way I'm animating the character. This guy is animated through a heavy list of poses in one pose morph tag, and for some reason, Octane's motion blur isn't liking that. I did end up being able to successfully render motion blur after stripping all of the poses out and only animating between a list of two that were both very similar to the base pose. I'll keep tinkering to try and pinpoint the exact issue. Will report back if I can figure out the exact problem.

Thanks

[jayroth]

Do you have vertex blur set up on your character mesh (located in the Object Tag>Motion Blur tab)? Also, try enabling Force Updates (Object tag>Main tab) -- that will send the mesh for every frame, rather than what Octane detects as changes. It will add to your render time a little, but it usually resolves motion blur issues in my experience.

If all of that fails, try baking down your animation into the mesh (several ways to do this) in Cinema. That removes any additional frame-based processing that Cinema would otherwise perform (and create possible conditions that Octane might miss.)

[jameskowalski]

Thanks for the reply and thought. I've got Transform/vertex on in the objectTag "motion blur" tab, as well as Force updates enabled in the "main" tab. The truly strange thing is that if I take the keyframes that are powering the pose morph tag and slide them up or down the timeline to some random new location, and render that new portion of the timline, motion blur will randomly work or not work depending on where on the timeline the keyframes are.... So strange.

I can consider baking all the animation down, but that is a tough sell when it comes to workflow / updates.

[jayroth]

I understand the workflow issues., believe me. Even so, baking might be your only option, given what you have written. At last until Otoy offers a comment about the issue.

If you have not yet done so, I recommend posting a scene with the problem and file a bug report. I have found that Ahmet is really great at problem solving once he has something to work with.

[jameskowalski]

Thanks! I actually can't upload it here because the file is too big... even with every non-essential element stripped out of it. Here are a couple more clues though.

I'm rendering quite far down the timeline.... North of frame 4000. When I move the animation to a frame number lower than 3500, motion blur seems to render more consistently (on the rigged model). Motion blur does work on those problem frames on simple objects that are in motion with Octane objectTags.

Here's what the console window looks like on two consecutive frames, one where motion blur rendered successfully, and the next where it did not.

frame 4044 (motion blur worked) :
FRAME 4044 fps:30
*** Calculating motion blur on frame:4044.1
*** Calculating motion blur on frame:4045
TIMES=4043 4044 4044.1 4045 time=876.962 ms.
MB:1/1 ST/MOV:0/1 Nodes:14 Tris:1.393m DispTris:0 Hairs:0 Meshes:1
VRAM used/free/max:576Mb/5.81Gb/8Gb Out-of-core used:0Kb total used RAM:20.954Gb
MotBlurTM=0.878 sec. createTM=0.224 sec. matTM=0 sec. updateTM=15.655 sec.
Device:0 TotMem:8Gb rtData:262Mb film:10Mb geo:316Mb node:2Kb tex:0Kb unavailable:1.627Gb temperature:64
Device:1 TotMem:8Gb rtData:262Mb film:10Mb geo:316Mb node:2Kb tex:0Kb unavailable:1.407Gb temperature:54
Device:2 TotMem:8Gb rtData:262Mb film:10Mb geo:316Mb node:2Kb tex:0Kb unavailable:1.376Gb temperature:58
renderTM:2.329ms. totalTM:19.096ms.

frame4045 (motion blur failed to render on the rigged model) :
FRAME 4045 fps:30
*** Calculating motion blur on frame:4045.1
*** Calculating motion blur on frame:4046
TIMES=4044 4045 4045.1 4046 time=858.33 ms.
MB:1/1 ST/MOV:0/1 Nodes:14 Tris:1.393m DispTris:0 Hairs:0 Meshes:1
VRAM used/free/max:588Mb/5.798Gb/8Gb Out-of-core used:0Kb total used RAM:20.89Gb
MotBlurTM=0.859 sec. createTM=0.207 sec. matTM=0 sec. updateTM=3.173 sec.
Device:0 TotMem:8Gb rtData:262Mb film:10Mb geo:198Mb node:2Kb tex:0Kb unavailable:1.627Gb temperature:65
Device:1 TotMem:8Gb rtData:262Mb film:10Mb geo:198Mb node:2Kb tex:0Kb unavailable:1.407Gb temperature:54
Device:2 TotMem:8Gb rtData:262Mb film:10Mb geo:198Mb node:2Kb tex:0Kb unavailable:1.376Gb temperature:59
renderTM:1.268ms. totalTM:5.517ms.

So the answer might be to break this animation up into more files, and keep everything on the low end of the timeline. For me, that will be easier than baking down all of the character animation. If I stumble upon some new info, I'll post it here. Thanks for the help and suggestions!