A method and apparatus for generating pixel shading values in a computer controlled display system. Generally, the apparatus is embodied in a rendering pipeline, where each stage of the pipeline performs a particular pixels shading function, so that pixels are shaded in a distributed and direct...http://www.google.com.hk/patents/US5706415?utm_source=gb-gplus-share專利 US5706415 - Method and apparatus for distributed interpolation of pixel shading parameter values 
