TEXTURED SPHERE AND SPHERICAL ENVIRONMENT MAP RENDERING USING TEXTURE MAP DOUBLE INDIRECTION

摘要

A system for rendering textured spheres and spherical environment maps provides for real time rotation of a textured sphere (501) and panning of the view into a spherical environment map (407), along multiple axes (502) without the need for special rendering hardware. The method is comprised of the steps of: providing a parmetric spherical environment map (501) of the image to be viewed, generating a screen look-up table (404) comprised of look-up addresses, generating a parametric look-up table (408) comprised of index values into the parametric spherical environment map, and for each look-up address (405) in the screen look-up table (404), mapping to an entry in the parametric look-up table (408), retrieving the value in the entry, and using the value to retrieve pixel values (411) from the parametric spherical environment map. Rotation or movement of the view being seen is accomplished by adding offsets to the look-up address and/or the index values.