A system for displaying three dimensional surface structures employs the analysis of voxel elements defined by eight cubically adjacent grid locations which are associated with at least one physical property defined throughout a three dimensional body. The physical property measurements may be made with such systems as computerized tomographic x-ray systems, or magnetic resonance imaging devices. Surface structures are defined by a user selected threshhold value such as distinct values for skin and bone in medical diagnostic applications. Selected voxels are subdivided and means are provided for generating signal values associated with intermediate additional grid locations. Means are also provided for generating surface normal vectors associated with these grid locations. The system of the present invention produces a sequence of signals representative of grid locations throughout the object being investigated together with associated surface normal vectors at these locations, the locations lying on a user selected surface. The system provides smooth, high resolution images which particularly useful for medical diagnostic applications and is particularly useful with conventional display processor hardware used for electronic graphics display. The capabilities of the system additionally provide enhanced flexibility and speed for the convenience of interactive users.