That's a great video - amazing effect!

I'm not projecting on a building per se, I'm just projecting onto a wall (screen). People will stand roughly 8' away from the wall and it should look like the room on the screen is an extension of the room they're standing in. So if they're in a 12'x12 room, and the imagery is of a 12'x12' room, then the end effect should be as if the people are standing in a 12'x24' with the additional 12' depth coming from the stereoscopic projection.

So in order to pull that off, the lines of the real room have to match the perspective of the projected image. For ex. the line between the walls and the floor have to appear to extend into the projected image at the same rate of perspective - if that's the correct term. Right now the projected lines (grid lines) bend too acutely.

I'm using a short-throw HD projector (Optoma GT720) mounted 9' off the ground at a screen (wall) that's about 12' away. It gives me a nice 9'x16' image. I'm afraid matching the Maya camera to the projector lens is going to be trial and error since this is a short-throw lens with special distortion attributes.

Other than the focal length, what other Maya camera attributes should I adjust in order to control the perspective angle? Sorry if that's not an accurate term - not sure what to call it