am I touching or inside an object?

is there a way for opengl to tell you if the viwer(if its size is well defined) of the world is about to touch an object and return the identity (we created it without an identity??!)of this object?
I am asking this because i am thinking if there is, in some case it may not be needed to keep the map /terrain and look through all of them to calculate to prevent you from going through an obstacle whenever you want to walk ahead.
Please tell me the conventoinal way to do this, thanks

Hi !

Short answer is no, you need to add some form of collision detection, OpenGL has no support for it, but there are a number of collision detection libraries out there, it depends a little bit on what kind of collision detection you want to do.

Mikael has great collision detection tuts. You might wanna check those out.