Idea: immersive video with one projector

This is an idea I had while lying in bed listening to Radiohead and hallucinating. (I was perfectly sober, I swear. The Bends is just that damn good.)

Build a frame structure (out of PVC or similar) with the approximate width/depth of a bed, and height of a few feet -- enough that you could comfortably lie on a mattress inside and not feel claustrophobic. Cover every side with white sheets, drawn taut. Mount a widescreen projector directly above the middle of this structure, pointing down. Then hang two mirrors such that the left third of the image is reflected 90 degrees to the left and the right third is reflected 90 degrees to the right (from the projector's orientation), with the middle third projecting directly onto the top of the frame. Then use more mirrors to get the left and right images onto the corresponding sides of the frame. (You'd probably also need some lenses to make everything focus at the same time; this is the only part I'm really iffy on. Fresnel lenses would probably be a good choice. Anyone who knows optics and has any idea how to set this up, please let me know.)

Anyway, the beauty of this setup is that it allows one to control nearly the whole visual field with a single projector and a single video output, thus minimizing complexity and expense. It's not hard to set up OpenGL to render three separate images to three sections of the screen; they could be different viewpoints in the same 3D scene, although as usual I'm more interested in the more abstract uses of this. In particular, you get control over both central and peripheral vision, which has psychovisual importance.

I'm really tempted to build this when I get back to Tech, but there's a high probability that someone else's expensive DLP projector will suffer an untimely demise at the hands of improvised mounting equipment.

Edit: I thought of an even simpler setup that does away with the mirrors and lenses. Make the enclosure a half-cylinder, and project a single widescreen image onto it (orienting left-right with head-feet), correcting for cylindrical distortion in software. The major obstacle here is making a uniformly cylindrical projection surface, but that shouldn't be too hard.


  1. I must say you have an astonishingly good idea there . .

    If I eve accidentally parylise|blind|maim myself, its up to you to reconnect whats left of my nervous sytem to the internet.

    If I can't move I want to live in a bed surrounded by this, and have my motor cortex generically rewired to a computer interface.

    If I cant see I want you to either tap into V1 or build something that sends a sweeping 1D FT of visual data to the audio system.

    etc etc . .

  2. oh.. you don't need corrective optics if you can build the correction into the mirrors.