1. A method of rendering a computer image formed of a plurality of pixels, comprising: identifying a first set of pixels in the image that have properties for which raytracing is advantageous; rasterizing the image, wherein an array of direction vectors is created as part of the rasterizing, the array storing a direction vector from a virtual camera and associated with each polygon vertex in the image; identifying a second set of pixels, wherein the second set of pixels is comprised of those pixels in the first set of pixels which are also in the foreground of the image; and, spawning at least one secondary ray from the second set of pixels, wherein the at least one secondary ray is spawned based on the array of direction vectors.