Subject: Calculating collisions

Hello,

I'm in the middle of a technical programm that is emulating
the Laws of Physics. I am trying to visualize how two
objects collide. My question in this matter is:
What is the best way to calculate this in a 3-D environment.

Do I have to divide my objects (of any kind) in small pieces
and calculate for each 'box' the collisions or is there a
way to calculate mathmatically with equations.

Please do help

Re: Calculating collisions