360 degree dot pattern projector - Help?

I am trying to cover an entire room with IR points from a central projector, something along the lines of this:



This is for a computer vision project I am working on, using realtime feature tracking to figure out the orientation and position of a camera. Using natural features is lighting dependent and very hard to get right, but most of the same techniques would apply to tracking these IR dots spread throughout the room. Basically, I want artificial natural features!

I have built out a 180 degree prototype using twelve 10mw IR laser modules with a dot pattern diffraction grating (~45 degree spread) I glued on, and it seems to work well. I want to figure out how to make something that can project in all directions without using so many laser modules, a single diode would be ideal.

Does anyone have ideas on how I could accomplish this? None of the diffraction gratings I have seen give a wide enough spread, the only thing I can think of is shooting through a bunch of partially silvered mirrors angled in different directions. I would greatly appreciate any ideas!