The Wiimote with Multiple Sensor Bars

Summary

The authors wanted to develop a tracked virtual reality controller that can be used in low-budget non-technical scenarios. They used 5 wireless sensor bars with 2 IR sources each, a Wiimote controller, and a Nunchuk. They placed the bars vertically along a 2 display VR environment. Some of the constraints include having 2 IR sources visible at all times, 2 sensor bars are visible when moving from one bar to another, and no more than 4 sources are visible at one time. For each iteration:

1. The software groups the tracked IR points to determine which pair is from the same bar. Then it creates a new dynamic model.
2. It determines if it confirms or contradict the existing model.
3. The software aligns the dynamic model with the static model using the previous alignment as a guide.
4. The software derives the scaling function using the IR points and their corresponding screen coordinates
5. It computes the cursor location.

They performed 3 tests. The first test was aimed a determining whether the visual disruption of the MSB array in front of the display would be distracting. The study consists of 12 participants and were given a navigation task of locating characters in response to audio cues and a manipulation task of stacking boxes on top of each other using the games physics engine. No one said the bars were distracting.

The second phase was aimed at establishing the usability of the complete MSB interface with a demanding FPS game.The authors wanted to see how often the game reset. 8 participants were in this study where they would complete two early levels from Half-Life 2. Some participants had trouble with vertical aiming and resetting.

The third phase involved moving the seat further back inside the coverage area. Some of the participants were from the second study and had high levels of reset errors. They were asked to replay the first level and a custom level where most of the enemies were at the horizon. The reset error rate dropped for all participants.

Discussion

I like this way of FPS interaction. The way they used the Wiimote was very intuitive, since it was like you're holding the gun. However, 2 handed guns may not feel right, and the other hand must be free for movement.