How to use Box Collider limited Camera in a Area

How to use Box Collider limited Camera in a Area??

For example :
I have a room . I use Box Collider around the wall and the ceil. So the MainCamera (Don’t use CharactorController Only Camera). can move in the room and Can’t throught the Wall and the Ceil…

I think this is a BASIC Question!. So How to do this ? PLEASE… HELP…

Try to use a Sphere Collider and a Rigidybody with “use Gravity” option disable on GameObject. It was what I did to simulate a helicopter Cam. It worked to me.