This is very easy in theory and practice, but produces some errors.
There are some particles falling (colliding) with the floor, and there is a ball with animated radius.
I want the ball to be copied to a particle when it hits the floor and ofcourse it's animation should start at that moment.

I tried several ways, ended up with creating an attribute which value is the exact nr of frames (or time - to limit rounding errors) of which a copy animation should be offset.

The value checked in spreadsheet is ok I checked it frame by frame, no matter if the particles are cached, roped to file or played frame by frame.
The problem is that some copies are offset good, while the others are completly crazy and does not reflect my offset attribute in any way.

What could this be? I'd be grateful for any links or thinks .

Perhaps this was not too clear
What could be the simplest way to offset animation based on particle attribute/event.
Animation should start when a particle hits collision object.
The details are in my former post.
This should be really easy but I have some unusual troubles.

Well, there were some problems with your file that I've fixed in the attached file:
- I changed it to just shift by hittime since that is the most straight forward way to do it. I don't understand what you're trying to do with the offsetFramesCreate node.
- The proper time to use after offsetting is $T-$hittime
- In your expression for stamping in the Copy SOP, you're using $PT but with a template group. You should using $TPT instead. Note from the help:
The point number of the Template being copied onto. If there is a template group, this will be the index into the group, not the actual point number. Use TPT to always get the actual point number.

Edward!

Thanks!

The problem was $PT as you wrote.
The rest of the mess was from my testing.
The “offsetFramesCreate” just created an attribute with exact offset value in frames to check its values and avoid errors.
I tried a lot of things…CHOPS, different expressions, shifting by frame, shifting by time.
It'd probably take a very long time for me to get to TPT which I didn't know about. Mysterious enough

Thanks a lot.