Perception of object shape in computer graphic displays

Three-dimensional computer graphic displays contain the information that vi ewers use to understand the shapes of depicted objects. We have devised tec hniques for carrying out experiments that examine the factors that influenc e the accuracy of this shape understanding. We construct simple convex obje cts using the superquadric equation. The objects are graphically rendered a nd displayed in rotation in a variety of perceptual tasks. In this paper, w e summarize the results of our previous experiments that examined the relat ive contribution of shading and occluding contour, and the effects of inclu ding specular reflectance. We also report experiments designed to determine the influence that light source direction and surface striping have on sha pe understanding. (C) 2001 SPIE and IS&T.