I want to copy an animated object onto another one using a moving bounding object to select template points, so the copies would appear and die. The only problem is I'd like them to start their animation on creation (and perhaps end on death), for example cones growing on a sphere.

I haven't learned pops yet but I think it's quite an easy task with their help.
Is there a way to do it without pops, In houdini escape?

Peter

The first idea that comes to mind is to keep track of the points' group membership at the previous frame as well. Then you know when a point has been created/died/dead/alive by comparing the point's group membership with the previous frame. Copy stamp this information and offset your animation based on this. Stamp the group membership point attribute into primitives and you can delete all the extra copies after the copy sop.

I was thinking something similar as edward, but instead of remembering past group memberships, I would create a kind of "soft-membership' by grouping the points based on a sphere bounding object, and then using the distance to the center of the sphere as the factor on the animation – so as the point is just added or just about to be removed from a group, the animation would get more faint. All points that are within the sphere are copy-stamped so have some kind of animation on them.

George.

Sorry to be so late,

Thanks for your suggestions, I haven't tried anything yet though.

I'll post my results if I'll solve this.

Peter