From: Bruce S. <bas...@un...> - 2003-09-04 23:11:53
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When Hugh Fisher recently brought 'active' stereo to my attention, I found it a bit difficult to figure out what kind of equipment to buy. So I offer my experience as a novice. I bought a PNY nVidia Quadro 750 XGL video card for about $350. The name "Quadro" refers to the fact that it has two double buffers, one for each eye (VPython draws a scene into one buffer while the screen is refreshed from another buffer, hence the term "double buffer"). I bought expensive shutter glasses from NuVision (now MacNaughton Inc.). The $270 wireless 60 GX comes with IR emitter to synchronize the glasses with the left/right images displayed alternately on the screen. Additional glasses (so several people can view the same screen simultaneously) cost about $250. These glasses are quite nice. I also bought cheap $35 shutter glasses from VRex. These are less robust mechanically and have smaller lenses, but they work fine. The connection to the computer is with a wire to a connector that goes between your video card and your monitor (and which delivers the synch signal to the glasses). John Zelle has been using 'passive' stereo. With a video card that can support two monitors, the program essentially generates a window twice the width of one view, and the card sends the right half to a computer projector and the left half to another computer projector. These projectors aim at the same screen (are located near each other), and they have polarizers over their lenses. You view the screen with 'passive' polarized glasses (just polarized glasses with the polarization directions at right angles to each other). Both left and right images are simultaneously on the screen at all times, but each eye sees only one of the images. You have to be careful to buy a screen that doesn't destroy polarization; I'm told that standard screens typically don't work. Bruce Sherwood |