Hi.



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.

I managed to do it using .abc file, the entire destruction in one abc file that have material references baked in. add a alembic ROP after the "transform pieces" SOP and check the entire sequence. load it in in another OBJ and gasp at the first pixel speed.

Also delete most/ all the attributes since the file is going to be insanely large, but its worth it.

if Someone know any other way to decrease the file size then please enlighten me