Offseting Animation on Instanced Particles (Flock of Bats)

[wintagreen]

Hey guys,

 

I have a particle system that is meant to mimic a flock of bats, and I've instanced a bat object onto each particle. The object has animated wings inside of it. Is there a way to offset the bat's animation so that the all the wings don't flap at the same time?

 

Any help would be appreciated!

bats_simple.v23.hipnc

[paulh]

Here's one way -> copy sop bat geo onto particles with a randomizing TimeShift node.

 

 

bats_simple.v24.hipnc

[Juraj]

Hi,

in case you have tons of bats (copy is not very memory friendly), you can use Houdini instancing, which is very efficient.

Recently I have done the same thing and I used this expression to load animation from disk. I used it for Arnold but with Mantra it should be similar.

$HIP/cache/birds_cycle_ass/cycle_`((($F + instancepoint()) % 9) + 1)`.ass

It will randomly offset animation cycle which consists of 9 frames written to disk. Not sure where you should put it with Mantra but instancepoint() function works only at object level.

 

Hope it helped.

[djwarder]

Hey Jurai, any chance you could give some more info about how you got the instancing working in Arnold please?  At the mo, I'm using fast point instancing with off-disk geo in Mantra but need to export this as .ass files to render in Arnold in Maya.  Is this possible at all?

[Juraj]

Hi,

I think it should be possible but haven't tried it yet.

Maybe this page could help you.