Store Position of Particles

[keirebu-niiru]

is there any way to store the positionarray of a particlecloud at one specific frame, to reuse it at other frames. How can I do it. I want the particles to remember where they were at this frame, so they can try to return back to there original position. I think my script now, can not remember these positions at all and provides an undefinded variable.

Thanx for any kind of help

Cu Sanostol

PS: Where can I find some related scripts to study.

[keirebu-niiru]

hello?
anybody out there?

a very disappointed and sad sanostol

[oozoux]

Are you running your script from inside the particle loop? this means that currently your script is loaded and compiled at every frame, instead of compiled once with an update entry point like the scripted operator.

This means that unfortunately, you can't have any data inside your script that is persisted during the sequence.

The quickest work around would be to write the particle positions somewhere else at the first frame, and then refer to that for the rest of the simulation.

one option would be to use a file to store the data.
another one, would be to create a dummy object (a spline) with as many points as your particle cloud, and use that to store the positions.

Olivier Ozoux, SOFTIMAGE Special Projects

The opinions expressed in this forum are my own, and might not represent's Avid or SOFTIMAGE official position on the subject.

[keirebu-niiru]

Thanx for your reply,

xsi stores already the data in a ptp file so it should be possible to access it within a script. do you know how the datas are stored.

By the way, in my recent project i had a huge simulation with particles ( the ptpfiles per frame are over 10 MB ) and i wanted to use one finished simulation over 800 frames for rendering, but even if i activatet the "UseForRendering" checkbox it calculates it again if I want to render it from batch. So if the render brakes, every finished frame is useless.

any suggestions ?

[devdoka]

In reply to:
Thanx for your reply,

xsi stores already the data in a ptp file so it should be possible to access it within a script. do you know how the datas are stored.

By the way, in my recent project i had a huge simulation with particles ( the ptpfiles per frame are over 10 MB ) and i wanted to use one finished simulation over 800 frames for rendering, but even if i activatet the "UseForRendering" checkbox it calculates it again if I want to render it from batch. So if the render brakes, every finished frame is useless.

any suggestions ?

The recompute issue is a bug and should be fixed in an upcoming release as was posted a few weeks ago on the XSI mail list.

For now, try exporting mi2 files and render from the command line. If the render fails on a frame, just try again and you won't lose anything.

Matt

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Matt Lind
Animator / Technical Director
Softimage certified instructor:
Softimage|3D
Softimage|XSI
speye_21@hotmail.com