Hi ,

I would like to replicate this effect : http://vimeo.com/35430285 [vimeo.com] (at 00:50) or on this video : http://vimeo.com/35145361 [vimeo.com] (at 02:00)

and i'm facing some (noobish) problems/questions :

1) How i can make primitive start their own animation only when they are inside a group (bounding sphere for exemple)

2) is it possible to give some noise or fallof to a group made by a bounding sphere? to give some randomness

Hope someone could give me some advices /guidelines ,

Thank you.
Sly.

The easiest way to accomplish this effect would be with particles on which you instance the geometry with the copy SOP.
Basically you activate the particles with a group POP (for example a torus with animated scale), give them an an upward force for a couple of frames and a downward force to get them to come down again. Then a collide POP should help you to let them rest at their original position again.
Now you need to know at which frame the particles got activated (attribute POP) in order to interpolate the 180 degree rotation. That's it
There was a tutorial on the 3dbuzz Technical Effects DVD (by Peter Claes) who did exactly this kind of effect, you might wanna check it out!

cheers,

Manuel

Edit: You can do the noise easily if you do the grouping in a VOP POP instead, this way you can easily jitter the positions of your points around without having to change their actual positions!

Hi,
cool video > See attached for a 10 second idea using a primititve sop. You of course will need to refine the idea as the transforms are not perfect but the system would work well with groups

Rob

Not a direct answer to your question, but you might like to check that hipfile out: http://forums.odforce.net/index.php?/topic/7248-peeling-spheres/ [forums.odforce.net]

wow! i didn't expect such quick help/answers. Thank you to all of you . i will read/watch all the suggestions and will look at the hipfiles.

i ll be back as soon as i get something cool to show (or problems i can't resolve )

Thanks again.

Sylvain.