Depicting three dimensional surfaces in such a way that distances between these surfaces can be estimated quickly and accurately is a challenging task. A promising approach is the use of semi-transparent textures i.e. only some parts of the surface are colored. We conducted an experiment to determine the performance of subjects in perceiving distances between an opaque ground surface and specific points on an overlayed surface which was visualized using isolines and curvature oriented strokes. The results show that response times for curvature oriented strokes were faster compared to isolines. For a trusted interpretation of these results, a plausible explanation has to be given. We hypothesize that users visually integrate the available three dimensional positions and thereby come to an estimate. Further experiments were carried out in order to formulate a model which describes the involved perceptual process as several attention shifts between three dimensional positions. The results of the experiments are reported here.
['Michael Kleiber', 'Carsten Winkelholz', 'Verena Kinder']
Model based evaluation of human perception of stereoscopically visualized semi-transparent surfaces