I'm currently unable to obtain motion blur on render using Houdini and HtoA for a destruction sequence in a shot.

This is a standard rbd setup using a packed .bgeo.sc geometry file. I am transforming this geo using the bullet simulation points transform attributes with the “Transform Pieces” SOP. It allows me to have @v attribute on my packed geo but Arnold doesn't seem to pick it up even though motion blur is enabled on my ROP.

It seem to be due to the fact that my geo is packed since upacking it and transfering @v from the packed geo to the unpacked geo allows motion blur to work. This is a very noticeable performance hinder at render time since the geo is heavy and unpacking adds useless overhead.

I was wondering, what is the proper “clean” workflow to render rbd simulation sequences from Houdini with Arnold? Would creating a .ass archive solves the problem? If so, do i have to export each frame, unpacked, to the archive? If so, it seems like a waste of hard drive space and time…

Hoping someone can shed some light on this.