Mirage 2000 User Manual page 91

OPERATION
Software Requirements
Customizing the
Input Signal
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Mirage 22000/4000/6000User's Manual
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IR EMITTER
: In response to an incoming sync signal, this small device emits
left/right IR signals to a receiver in active 3D glasses, causing their left/right
shutters to alternately open and close for active 3D application. Connecting an
emitter to the emitter port on the Stereo3D
you to switch back-and-forth between active and passive systems, if desired.
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GLASSES
: Active glasses differ in speed/performance—consult the
documentation for your glasses and keep their specifications in mind when
reconfiguring your source signal. The input signal must be optimized for the
available shutter speed in order to prevent obvious "ghosting" of image
content (known as cross-talk in 3D applications) as well as other more subtle
color artifacts. Such problems indicate that the eyes are detecting portions of
the opposing frame due to an "out-of-sync" system, and can occur in either
active or passive 3D configurations. See Customizing the Input Signal, below,
for examples of well-synchronized systems.
NOTE: In a passive system, where glasses do not have shutters and instead
depend on the speed and accuracy of the Pi Cell polarizer, the input signal
must be synchronized with the polarizer.
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MIRAGE PROJECTOR
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To customize your 3D input signal for use with the projector, you will need access to
software that controls video output timing from the graphics source. For example, the
Video Format Compiler (vfc) and ir combine are required when using the Silicon
TM
Graphics ONYX
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The display must be synchronized with shutter control—called gating—so that each
eye receives only the frames of data intended for it, otherwise you will detect
opposing data frames (cross-talk) and see faulty images. This requirement means that
timing parameters in your source should guarantee the following:
1) Each new frame begins after the opposing shutter mechanism is closed
2) Each frame completes its display before the opposing shutter mechanism
begins to open.
3) Each frame (mirror sequence) is displayed in its entirety to the correct eye.
What To Adjust
Since current 3D-video sources do not have the necessary characteristics for use with
this projector, you must synchronize the projector's display with your gating
mechanism by adjusting the vertical sync width and/or vertical back porch of the
input signal and, in many cases, by adjusting the projector's Dark Interval control.
These two parameters—input timing and dark interval—are described below. Note
that because they interact with each other, you may have to go back and forth
between them when optimizing the 3D display. In general, vertical frequency + Dark
Interval/10 = 110 Hz or less.
1) Vertical sync width and/or vertical back porch blanking of your input source.
Choose the vertical sync width and/or vertical back porch timing to determine
when the next field begins displaying relative to the vertical sync signal. The
degree of timing adjustment needed depends on the specific signal at hand as
well as the performance of your glasses. An example of improvements to poor
synchronization is shown in Figure 3.35. After adjustment, shutter changes
occur during the dark interval between frames.
workstation.
TM
Interface Module also enables