Camera pass through wall

I Have a 3D mall made in studio max and imported to unity as FBX and in unity when i put a camera to walk in the mall it pass through the walls and objects, like if the objects didn´t exist.
Please can anybody tell me how can i solve this question??

Thanks

You have to have your “mall” set as a rigidbody without gravity, as you don’t want it to fall. And you have to set a collider on the camera, such as a box or a sphere collider so the program knows whether or not to look for collisions with that object. =D Good luck!