3d Concepts by the Sighted, the Blind and from the Computer

A tactile rendering system has been developed to create tactile drawings of 3-D scenes for blind people. The representation of 3 dimensions in pictures for the blind has been a long standing problem. The current paper considers spatial concepts by sighted people, by blind people and in the data structures of a computer. The mapping of spatial concepts as pictures in a two dimensional format is discussed. Various differences in the representation of 3-D visual and tactile pictures are noted. Techniques used in drawings by blind people as observed by the authors and others, have been employed in the development of the tactile rendering system. This is able to use several methods in one picture of a scene of several objects for a blind person.