I'm assuming you created your level geometry completely in C4D and then when importing ticked "generate colliders".
While this works well for quick tests and single complex objects, you should generally use simple colliders to mark up your scene in Unity. Not only are these much cheaper performance-wise, but also more precise. This also ensures that you know exactly what is going on in your scene physics-wise.
Notice that it is a good idea to make the colliders a bit too "tick" - in case of walls you could just ensure that the excess collider is inside the walled up area. This helps make sure that the collider is respected by fast moving objects.
answered Mar 18 '10 at 10:50 AM
The only thing I can think of is that the normals on your collision geometry might be inverted from what you are expecting.
You will have to be more specific in order to get a more accurate answer, but I find that is a general problem I see upon receiving geometry from other artists during integration.
answered Feb 18 '10 at 12:28 AM
Sometime the speed of the player can be an issue...but is is also related with the TIMING your game use (Project/Time options) and also the physics.
Is your FPS player a rigidbody ?
Does it fall madly from big heights ?
Be more specific!
There is a script in the WIKI which use RAYCASTING for avoiding these problems, but usually, you won't need it.
answered Feb 18 '10 at 03:21 AM