detection of touching of 2 models

Hi, everyone!

I have a set of irregular shaped models.
let’s say, among these models, there is a pond and a boy.
the position of the two is known.
And I want to detect if the boy is touching the pond.
that is, If any part of the boy has a joint section with the pond(even a finger), the system should give a warning that the boy falls inside the pond.

How can I do that?
Thanks!

yar, to make my question clear:

the models are 3D models.

the models are load from wrl files

the position of the models are given, but not set by the program.

hi chaosy

There’s a free library for collision detection called I_COLLIDE available that you might find useful.
http://www.cs.unc.edu/~geom/I_COLLIDE/index.html

Greetz
Markus