PIBiped001 is a template action for players. I don't know if you can set seperate settings for collision detection in a template function.

3DGS uses a bounding box for collision detection.

If you want to create your own player-movement you have to use c_move for collision detection:
http://manual.conitec.net/ac_move.htm (here you can also see what options are possible to set for collision detection).


[EDIT] Aaahhh ... and welcome to the 3DGS Community