Hi, can anyone help me. i'm creating dop simulation (fractured object) in Houdini, render geometry as sequence .obj then import them into modo to be rendered . Problem is : i like to have real motion blur from the fractured animation. How can i do this inside Houdini (maybe like passing velocity attr - but don't know how to do it) ? does anyone has experience on this ? is it possible ? pls help.

thanx a lot.

I believe the DOP Import SOP should be attaching the velocity of each object as a point attribute by default. If you are not using that you should be able to create a point attribute using a dopoption() expression that gets the velocities for each object.

Hi Graham, thanx for replying. Sorry for delay, busy busy day. Ok i have applied (adding) velocity attr … no problem. But i just found out that it's the modo which can't translate it well (things works well in houdini - so the problem is not in houdini ). I just got replying email from mr.Stenson, who wrote a houdini-modo plugin for .obj sequence importer. He said it's not possible at the moment to pass data for motionblurring the simulation from houdini to modo , so he suggest me to use .mdd. I'm still having hard busy day, so got no time to try it. Last time i create a succesfull mdd, but when import in modo, it just empty scene. I will report soon i got this things fixed.

thanx

Why don't you import it via mdd? Works nice for me…

calix
Why don't you import it via mdd? Works nice for me…

yes , i'm trying mdd now, but still got some problem. I try simple box then i rendered out as mdd but it is just empty. Even when i imported back to houdini, there's no object at all. any idea?

mdd does not contain any object, just point positions for each frame
you need to import object first (e.g. .obj) then MDD pointcache

also exported object should have constant point count for the whole animation length for mdd to work

so dynamic fracturing cannot be transfered this way, but prefractured geometry surely can

tamte
mdd does not contain any object, just point positions for each frame
you need to import object first (e.g. .obj) then MDD pointcache

Perfectoo, thanx Tamte , i missed that step.