Progress report for the comp 239 final project. (Nov. 19, 2002)

Redirected walking enables a person to have the impression that they are exploring a large virtual environment. In the virtual world the person may choose to walk, for example 20m in a straight line. The longest part of the lab space might only be 5m. Although the person could not walk 20m in the lab space, redirected walking can give the person the illusion of walking 20m. To walk 20m in the lab, the person has to walk four times back and forth along the 5m length of the lab. At the end of the 5m the person has to be rotated 180 degrees in order to walk the next 5m. The person’s sense of presence, however, would be broken if they consciously had to turn the 180 degrees. Instead to maintain the presence, the person must rotate without being aware of it. The redirected work by Sharif demonstrates how to rotate the person unknowingly to him/her.  While the person rotates his/her head, the virtual world is rotated. The person does not consciously perceive the rotation, but compensates by also rotating. Hence the person is rotated but has the impression he/she is still walking in the same direction. So to walk the 20m, at the end of every 5m, the person has to be rotated.

Rotating the person and virtual world requires that the person rotate his/her head. The objective of this project is to find a way to predictably have the person rotate his/her head. The approach taken is to distract the person with an activity when they reach the end of the 5m length. An example to distract the person is to have a butterfly appear in the person’s view. The butterfly is like the tour guide of the virtual world; it shows the person where to go next. The butterfly flies about the person’s head. The person will be interested in the butterfly and continue to turn his/her head to prevent the butterfly from leaving the person’s field of view.  While the person rotates his/her head the virtual world is also rotated. After the 180 degree rotation is complete, the butterfly flies to the person’s next destination, which corresponds to the opposite end of the 5m in the lab space. The process repeats itself until the person has walked the 20m.

Previous documents

• Idea: Audio navigation aid for the blind
• Redirected walking for campus

To complete the project, I have divided the workload into stages that I can independently complete. The stages are as follows:
 
• Rotating the virtual world around the person’s position. Sharif explained the Math involved in rotating the world. I have implemented the Math in Matlab to verify it. I am working on the implementation in VR-juggler. It is more difficult to implement in VR-Juggler because it is harder to debug errors in the graphics.
• The next stage is to distract the person with the butterfly. I have to implement an interesting motion for a lively butterfly. It would be useful to have more ideas about activities that can distract the person.
• Choosing the virtual world. The choice for the virtual world is changing as the objective of the project changes. Originally, the objective was to provide audio cue to help blind people navigate on campus. Then the objective became to navigate about campus. In these cases it was appropriate to make a virtual campus. The current objective is to investigate how to distract the person without breaking the person’s presence. In this case the virtual world can be any arbitrary world. A long room will be in the simplest way to demonstrate how the redirected walking works.