I did a quick test with your scene and the problem come from your abc export without enough sub-sample and deforming (interpolating) the geometry between key frame. To counter this, I froze the animation on the first frame and linked the object to a locator, and the problem is gone.
Maybe try to re-export your geometry with more sample, or keep the hierarchy in your animation package.
Thanks for your input. I found the "problem" I didn't tick the "Use Motion Blur" in Houdini's ROP Exporter. If I do so, then I need to to chose Motion Blur Mode "Use Sub Positions"
But what is the option to "Compute Velocity" out of an alembic then?
- read velocities : just take into consideration what have been exported (based on the sample you define in your DCC) - compute velocities : based on the MB Sample count, Shutter Begin, Shutter End you defined in the path tracer. Most of the time if you place the mouse over an attribute you display the tool tip, giving you a quick definition of the different options.
Cheers
Aymeric Isotropix Technical Artist - Clarisse Specialist