ACTIVE VISION AND THE IDENTIFICATION OF 3-DIMENSIONAL SHAPE

We examined the performance of human observers to identify three-dimen sional (3D) shape from motion induced by exploratory head movements. S ubjects categorized 3D quadratic surfaces with randomly chosen shape b ut with a fixed amount of curvature in one of eight shape categories. Human observers had their best performance with convex parabolic and c oncave parabolic shapes, but had more difficulties in identifying the hyperbolic shapes. The identification of 3D shape was not significantl y influenced by the amount of curvature. This means that our descripti on of 3D shape closely matches the intuitive notion of shape, and that its use in 3D shape perception tasks is justified.