Thank you for your quick answer. I promise I woun’t use Photoshop Live 3D anymore, but I now need to finish the project with it because I have no access to other softwares right now.
The main problem is quite simple: How can I fixate the houses to the floor?
In this video you see them under, over, on or aside from the floor:
https://docs.google.com/file/d/0Bx4pDXBvGiq5TmFuX1hkS0V1R1k/edit?usp=sharing