Visualization Lab Display Systems

All stereoscopic graphics systems rely on the computer creating two images of a set of data or a scene - one from a perspective of the left eye, and the other from the perspective of the right eye. After the two views are created, each image must be visible only by the appropriate eye. In the Visualization Lab (Vislab), this is accomplished with glasses.

The desktop systems display the two views alternatively, so that the CRT monitor displays a frame for the left eye (while the LCD shutter glasses cover the right eye) and then the right eye (while the glasses cover the left eye). The projection system separates the left and right views and sends them to individual projectors. The output of the projector passes through a polarizing filter that is matched with the filters, appropriate for each eye, on the lightweight, polarized glasses.

Each Vislab computer is setup to display stereo and each Vislab software application has a different way to activate the stereo display. Usually, in addition to turning on stereo, there is a way to adjust the degree of stereo separation. When adjusting the stereo separation begin with something small and increase the separation until the image "pops out" and looks 3-dimensional.

Display Set Up

All Vislab computers are set up with two stereo display outputs; the main display (the one you initially log onto) is routed to the CRT monitors and the second display goes to the stereo projection system. Both the Suns and PCs situate the two displays as a part of a large virtual desktop with the main CRT display on the left and the projector display on the right. On all machines, by moving the cursor to the right of the CRT display it goes into the part of the desktop that is displayed on the projectors.

Under Solaris on the Suns, the two displays are referenced differently. Users are able to direct where output appears by using the DISPLAY environment variable. The main CRT display is ":0.0" and the projector is ":0.1". Under C-shell, to make subsequent windows appear on the projector display, you must issue the command " setenv DISPLAY :0.1 ". Borne shell users (including bash and sh), need to give the following command: " DISPLAY=:0.1; export DISPLAY ". Note: Windows that appear on :0.1 can only be viewed with the projectors turned on and the computer source selected. See Projection Stereo. In the current set up for Solaris, windows must be in only one of the two parts of the desktop and cannot span across two.

On the PC's, the desktop is a large single one that has the left display on the CRT monitor and the right display on the projectors. Users can move a window between them or have it straddle the two. Note: Maximizing a window, will maximize it into the part of the desktop which contains the window control buttons (in the upper right corner of the window).