Crystal Eyes Stereo

Crystal Eyes stereo refers to a special hardware option available on Silicon Graphics workstations that allows one to view three-dimensional objects through the use of a special display monitor mode and special stereo viewing glasses. Stereographics Corp. is one such supplier of these glasses. This mode also requires special infrared emitters to synchronize the stereo glasses with the display monitor.

There are presently two types of Crystal Eyes stereo modes available on SGI machines; which one is used depends on the available graphics hardware (see the man page stereo(7)). Follow the outline below for the relevant graphics option:

Stereo in a window (aka new-style stereo):

Available on workstations equipped with Reality Engine2-style graphics subsystems only (such as Onyx or Power Onyx machines), this mode provides separate left and right eye frame buffers. It allows the user to have a window display in stereo, and the other windows appear as normal. Using this mode, however, requires the monitor to be in a lower-resolution 960 by 680 display mode. The monitor must be set in this mode before starting VMD. To do so, do one of the following:

• If superuser access is not available, and the monitor is in the normal 1280x1024 mode, execute the command:
  /usr/gfx/setmon -n 960x680_108s

  This will change the display characteristics to the lower resolution mode, with a higher display frequency (108 Hz), but will not change the managed size of the X-Window display screen. To change back to the normal mode (after running VMD), execute the command:

  /usr/gfx/setmon -n 1280x1024_60

  When the computer is in the lower resolution mode, run VMD as normal, but note that the lower resolution means the windows will appear larger and may end up sometimes positioned off-screen. If this is a problem, a system superuser should set the video mode permanently with the commands listed in the next item.

• If superuser access is available, do the following, which will change the video mode and restart the window server with the lower resolution settings. (WARNING: executing this command will log out anyone on the console)
  /usr/gfx/setmon -x 960x680_108s; /usr/gfx/stopgfx; /usr/gfx/startgfx &
  To reset the computer to regular 1280x1024 use, execute the command:
  /usr/gfx/setmon -x 1280x1024_60; /usr/gfx/stopgfx; /usr/gfx/startgfx &
  It may be useful, if stereo-in-a-window will be used often, to set the monitor to the lower resolution mode, and leave it that way.

Once set in the proper display mode, start VMD as normal, and select `Crystal Eyes stereo' from the Display form. The image should switch to two images nearly superimposed, but slightly offset.

Regular stereo mode:

All stereo-equipped SGI workstations can use this display mode, including Reality Engine 2 workstations. VMD uses two programs onstereo and offstereo to switch the monitor display mode. You will need to install these programs somewhere in your Unix path in order to allow VMD to use them. Regular stereo mode will change the display window to occupy the entire monitor screen, as opposed to stereo-in-a-window which can independently set the stereo mode of just the display window. Versions of onstereo and offstereo which will run on SGI IRIX 5.X workstations may be obtained via anonymous ftp from ftp://ftp.ks.uiuc.edu/pub/mdscope/vmd.