1. A method of displaying surfaces without interpolation, of volumetric data, having voxels with an aspect ratio A, voxel values each at a specified location and index, comprising the steps of: a) selecting a central voxel; b) testing the central voxel against a predetermined threshold; c) for each central voxel above the predetermined threshold: i. determining a plurality of diagonal voxels and their values relative to the central voxel; ii. comparing each diagonal voxel value to the predetermined threshold; iii. categorizing the central voxel as a surface voxel, if at least one diagonal voxel value is below the threshold; iv. calculating a surface normal vector for each surface voxel from differences between values of voxel straddling the central voxel; d) repeating steps "a"-"c" for a plurality of different voxels as the central voxel to result in a plurality of surface voxels and surface normal vectors; e) receiving a viewing angle of a desired view of the surface voxels; f) rendering the surface voxels and surface normal vectors at a desired viewing angle (azimuth, elevation .gamma.) to screen pixel data each having an (u,v) screen location, pixel color, and intensity as viewed from a modified viewing angle taking into account said aspect ratio, A; g) displaying the pixel data as an image to an operator.