I made some particle simulation in houdini, baked them as bgeo format, and imported them from file sop.
then, covered this geometry obj with subnet, and made them to be otl. (particles have v attribute only for motion blur.)

I imported these particles using engine in maya.
and wanted to render through Arnold renderer.

the problem occurs in this step.

when i render this sim with “motion blur” on, it takes very very long time.

the timeline bar starts to scanning all the frames from start to current each every frames to render.
status bar says just “calculating..”, but i think there is no need to be calculated because particle sim has been baked already.

and it doesn't need all the frames to be calculated for motion blur.. a few frames are needed.


is my way to render wrong? are there any alternatives?

or can i control the scanning range??


Pleas help!!
All the answers will be appreciated.



Thanks,

Eunchan.

I can't seem to reproduce the issue that you described. When I rendered frame 25 with motion blur, I see the frame jumps to 24.75 and 25.25 only. I don't see it starting from the first frame. I think the “Calculating…” text is from Arnold, rather than from Houdini Engine. I've attached the scene file that I used to test.

Are you rendering in GUI? Or batch mode?

Does your asset contain the particle simulation? Or does it only contain the File SOP?

It'd be great if you can post a scene file that can reproduce this issue.

In Maya's preferences, do you have “run up” enabled? If I enabled that option, then I see the behavior that you're describing.

Hi Andrew, Thanks for your answers.


I forgot something in my post. this problem occurs on “Millions of particles” simulation..
usually in less than 1M particles sim, it has done well. but if I use 3M~8M, than problem occurs in both modes of GUI and batch.

My asset contains only the file sop and ‘Run up to current time’ toggle is off in Maya preferences.

Have you tried to use millions of particles? if you have, and not occurred this problem, then it may be my system's problem..

I want to upload my scene file, but it contains very heavy sim and hundreds gb of particles bgeo… so it can't be possible. i'm sorry.. but I've tested about this problem in your scene with increasing the number of particles, than same problem has occurred. so I guess you can also test on it with only increasing the number of particles.


Again thanks for your endeavor Andrew!

I just tried using fairly dense particles with the scene that I uploaded. But I still can't seem to reproduce the issue that you described. Can you try using Maya's own particles, and see if you can reproduce the same issue?