Depth Perception

The nature of astromical data gives a soft, ``cloudy'' effect when volume rendered. This makes the task of implementing effective three-dimensional cursors more difficult. Even with the three-dimensional shaded cursor the user still finds it difficult to place a cursor accurately relative to a feature of interest.

The use of stereoscopic displays can help depth perception, but often the effect is not enough to allow the user to make accurate depth estimates. The stereo effect can be enhanced by changing the geometry of the eye positions. However, too much enhancement can cause the user to lose the stereo effect. Only users with high visual acuity can enhance the stereo effect sufficiently to place a three-dimensional cursor accurately. To cater for most users with average visual acuity requires an alternative, or an additional, technique.

© Copyright Astronomical Society of Australia 1997