When does collision fire with avatar?

I have an object that fires towards an avatar which has a script that includes the collision event. As I watch the object move towards my avatar, I can see that the collision event is triggered before it actually intersects my avatar. Is the collision event supposed to trigger when the object actually intersects the avatar's mesh, or is there some invisible bounding blob surrounding the avatar that the object crosses to trigger it? Thanks

Almost certainly a bounding box, but I don't know what effect attachments have on the avatar physical representation.

Also note that physical simulation has to use numerical approximation methods with - in SL - a clock <= 45 Hz, so there is some epsilon around that avatar collision domain.

there is a bounding box for all avatars. I forget the measurements, but typically it's larger than what the model shows. I believe using llGetBoundingBox() in an attachment will return your avatar's bounding box. also while it is a box in shape, you can use a cylinder to approximate the box and get near identical results for collisions.

upon collision object is in a position where, on the *next* physics 'tick,' it would have been intersecting. each 'tick,' the object moves its velocity divided by 45. the position you get from llDetectedPos will either be the position at that 'tick' (the one *before* intersection would have occurred), or sometimes it gives you a position from one or more 'ticks' before that

Wondering if it might be possible to delay whatever it is you're doing in the collision event for a few ticks until the object moves a bit closer? Or am I on the wrong track.. just a thought.


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