Generate camera trajectories in a box or a sphere after generating a single room

[GCChen97]

I tried to make indoor videos for some 3D perception tasks and noticed that camera trajectory generation was unstable. I saw compose_indoors.animate_cameras_enabled = False # not yet working robustly in base_indoors.gin.

For a single room case, it may be simpler to treat the whole camera trajectory as an invisible object and generate the actual camera trajectory in the object after generating the whole room.