Stereo and Multiple Channel use with HANK

by Jillian M Tidd and Lea D F Wittie

Project Overview and Goals

Our primary objective was to configure HANK, the driving simulator, to run with a stereoscopic display. Normally, when an image is displayed to the screen, only one image is displayed. In stereoscopic display, two images are displayed slightly offset from each other to imitate the two viewpoints of the eyes. The user wears special polarized goggles that alternately darken one eye or the other. The two images displayed are never on the screen at the same time; they alternate between left and right in sync with the goggles.

Because HANK is based on IRIS Performer 2.0, we started by trying to get Performer to run in stereo. Performer is an extremely flexible and powerful application for building visual simulations and virtual reality environments. It offers several resources for developers. Among them are the online help manual IRIS Performer Programmer's Guide, sample programs, and a newsgroup, that proved to be the most important source of information. And because HANK is so similar to one of the sample programs provided by Performer, called Perfly, any knowledge we could gain relating to perfly was helpful for modifying HANK.

For HANK, we needed to not only modify it for stereoscopic display, but also provide an option for multiple views and a simply way to use these options. We added in a command line option for the different files that HANK runs that allows the user to select between 6 different display settings. Among them are a standard view, stereoscopic, and as many as 6 views at once facing in varied directions. These multiple views will be used in experiments to provide a virtual environment that surrounds the participant. The subject can sit in the car and turn his or her head to both sides and even to the back still be looking at the scene. Providing a complete virtual environment is a key to getting subjects to treat HANK like a real car, on a real road.

The first section in our paper discusses how stereoscopic display works with the human visual system. The second section discusses what Performer's Perfly works, concluding by tracing the main function through its various functions. The third section discusses how to set up multiple channels in Performer and HANK, including all of the necessary code and steps to go through. The final section lists the changes made to HANK and how to use the stereo or multiple view option.

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Last Edited July 20, 1997