Collision for Russian Apartment Building

Hi to all.
By using blender, i have created a building with actual entrance, apartments and attic inside:






Is it possible to create a proper collision for all of that to player could walk inside any room and floor?

I already tried to create custom collision according to some tuts on youtube (copyed mesh, decimate it and write a UCX postscript), but unreal is just simplifies collision to a simple cube.

If custom collision doessnt work for you, you can add blocking volumes (from the list left of the viewport) within the level to act as floors and walls.

If you make just one collision object it certainly won’t be a convex hull, which is a obligatory condition. For a building this size you would have to make (in Blender) a bunch of collision meshes.