Depth perception and visual after-effects at stereoscopic workbench displays

The vivid and clear way of virtual scene presentation in virtual environments (VE) is nearly exclusively accomplished by stereoscopic displays. Depth perception with these displays differs from the viewing conditions in reality and causes usability problems. For this reason three important aspects of visualization at a stereoscopic workbench display were analyzed. The results of three experiments with terrain data as an example application show a significant increase of depth perception when using stereoscopy, while map texturing causes a significant decrease. For additional wireframe texture and head-tracking, no significant effects were found. With regards to the upper and lower bounds of stereoscopic visualization a linear relationship between the maximum elevation of single objects and the distance between fixation and projection plane was specified by regression analysis. Finally, it is shown that 1/2 hour activity at such a display does not result in negative after-effects for the visual system, including visual acuity, phoria, fusion, and stereoscopy. These results suggest the use of stereoscopic workbench displays for presentation of three-dimensional terrain data. In contrast, deficits of depth perception are verified resulting from overload of visual information, or from using a parallax which is too large for the presentation.