The Lighting Controller

I work at a skating rink, and I'm trying to figure out a way to set the room up so it isn't a true rectangle! The skating rink is kind of an odd shape! In the fact that it is kind of a stretched out octagon, is there any way to do that?

Build a 3D file of it and then import it as an .obj?

Or make your shape using the blocks that are in the viewer,this is what I do to create the stages in theaters, I 'box' them in by placing a load of the stage blocks in the room, sizing them etc.