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
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