I'm looking for the same sort of idea but in a different fashion, because I want a small portion of the ground to be a rubber material for a playground or something like, with shards of rubber to keep you from getting hurt, also from what I understand the area in question will at some spot next to that have trees possibly on top of a tiny Hill for sledding in the winter... Is there any way to not have walls and yet have a room design maybe on the floor to simulate a black rubber textured material, or perhaps there is a black textured rubber material in a texture file that somebody could import as if it was a object on the ground although the first one would probably be the preferable way to do it, and I have no idea how to add a hill but if I could add a hill in there to where it would be viewable in a 3D video render that would be great... I just found this particular thread online as one of the few threads I have found that even tries to tackle this particular subject or something even similar to what I'm looking for so anyone with any insights that might help me would be greatly appreciated...