摘要 |
A method of efficiently removing backfacing primitives from the graphics pipeline such that rendering efficiency is increased. In one embodiment of the present invention, a bounding cone of normal vectors of a primitive is first determined during pre-processing. During the rendering process, before the primitive is drawn, the bounding cone is compared with a half-space defined by a viewing vector. Primitives whose bounding cones do not intersect with the half-space will be removed from further processing. In this way, rendering efficiency is increased. In another embodiment, a normal bit-vector is used to represent normal directions of a primitive, and a visibility bit-vector is used to represent visible normal directions. In that embodiment, primitives are culled efficiently by comparing the normal bit-vector with the visibility bit-vector.
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