Motion blur not working on alembic object Tweet

[mikeadamwood]

I baked some simulated spheres on an object and it seems to work in LV but not in the final render...

I have a character in the scene but I cannot supply that in the file, but motion blue is working fine with that, so it everything else has motion blur in the scene...But the alembic import will not render with motion blur.

Here is C4D/Alembic:

MB_PROBLEM.zip

(2.56 MiB) Downloaded 78 times

info:
Windows 10, 3xGTX 1080ti, 64gb RAM, NVIDIA DRIVER 512.95, Octane Standalone v2021.1.5 + Plugin, C4D R26.015.

Octane MB is the bain of my life!

[aoktar]

I can see MB as I set "motion step=1". It's not working with more steps. How did you generated abc and export back?

[mikeadamwood]

I can see MB as I set "motion step=1". It's not working with more steps. How did you generated abc and export back?

It was just generated in C4D with the 'Bake as Alembic + Delete' option using just rigid body tags/collision tags.

[mikeadamwood]

Ok so I just did a test where I deleted the alembic object then merged it back into the scene...Had to reapply materials/octane tags etc but it seems to be working now when I render from frame 75..So hopefully it works on the full render.

If this works then it's something to do with the 'Bake as Alembic + Delete' function, which is really wierd as you'd think it would just be doing exactly what you're doing when you import as a file, just saving you the extra steps :/

It would be good if you could look at this to see if it's something you can fix as it's a much faster way of working especially if you have a complex scene with alot going on. Octane seems really temperamental when it comes to motion blur...Last few projects I've done has been for a client that insists on motion blur and it's caused nothing but issues..And the funny thing is you can't really take LV as proof it's working as like you told me in another thread, it's computed differents to the final render.

[aoktar]

You need to know the limitations for motionblur and differences for PV vs LV. It's a part to read in manual. LV is not giving exact motion data everytime and can't work with sub-steps for frames. Except on first send the scene, because it's creating a temporal scene to catch the data. After that during the interaction with objects or timeline you'll loose the some of required data and will not guarantee providing exact data. Apparently we have a problem with alembics like missing subframe data and this making you confused. As my tests I cannot get interval data as should be in other objects. Looks like a problem with scene evaluator or evaluation commands of C4D. That should be reason why it doesn't give exact motion data on Picture Viewer with step values.