Surface classification method for a microcomputer-based tutorial system of anatomy

For a microcomputer-based tutorial system, algorithms based on Surfaces have been implemented, using classification procedures for spatial position and normals of faces of anatomical structures, in order to establish a priori knowledge of visibility, distance and colouring. With the proposed approach reductions in computing time are always obtained, but the degree depends on the viewing angle. For a lateral-anterior view of the skull (31,873 faces), reductions of 33% were obtained in the number of read operations and 59% for visibility test.