Hi there
I am trying to render some motion blur on procedurally generated meshs (paint effects transformed as meshs).
The motion blur goes completly crazy on some frames and on some meshs parts, as some vertex had huge movement between frames. I checked the subframes in maya, and they are correct.
I tried baking the meshs as abc with subsamples (0.25), the subframes are ok in maya viewport but the same kind of moblur problem arise.
The vertex id of the meshs change per frame. Do Mtoa need a consistent vertex id during animation to calculate the motion blur?
Or does the problem come from something else?
Thanks
Solved! Go to Solution.
Solved by Stephen.Blair. Go to Solution.
Does the number of vertices change? Is there anything in the Arnold log?
The number of vertices does change between frames (the meshs is created based on another mesh deformations and the camera animation).
Arnold log throw those errors:
00:00:02 1517MB ERROR | [mtoa.translator] pfx_geoShape | Number of vertices changed between motion steps: 14655 -> 14600 00:00:02 1525MB ERROR | [mtoa.translator] pfx_geoShape | Number of vertices changed between motion steps: 15055 -> 15050 00:00:03 1532MB ERROR | [mtoa.translator] pfx_geoShape | Number of vertices changed between motion steps: 14655 -> 14610 00:00:03 1535MB ERROR | [mtoa.translator] pfx_geoShape | Number of vertices changed between motion steps: 15055 -> 15035 00:00:04 1539MB ERROR | [mtoa.translator] pfx_geoShape | Number of vertices changed between motion steps: 15055 -> 15070 00:00:05 1540MB ERROR | [mtoa.translator] pfx_geoShape | Number of vertices changed between motion steps: 14655 -> 14660 00:00:05 1541MB ERROR | [mtoa.translator] pfx_geoShape | Number of vertices changed between motion steps: 15055 -> 15035
It seems logical that the vectors can't be correctly computed...
Is it possible to set some velocity vector on an attribute vertex for mtoa to read at render time?
For a varying topology, you can use the motion vector source:
https://docs.arnoldrenderer.com/x/H4E7B