I've made the map using Blender. My walls are straight (90 degrees) and of my floor vertices are on the same height, even 2d collision would work here. That's why I won't bother with generating a collision map for now. Performance is not an issue at all for now.

Thanks to all for the suggestions. :wink:

Not knowing how many walls, needed flexibility etc, there are a lot of options.

If it's just for a test, you could get away with setting static boundaries where the walls are. For more flexibility I'd go for AABB checks or OBB / worldAABB if orientation is an issue.