Triangle-Level Depth Filter Method for Bandwidth Reduction in 3D Graphics Hardware

In this paper, we proposed an early depth test method which extends a pixel-level depth filter to a triangle-level depth filter. This method decides whether the triangles are removed as well as pixels by a mask plane called depth filter (DF). The proposed method evaluates the DF in the triangle-level by using a hierarchical map of the conventional DF; thus the method removes the invisible triangles before the rasterization. Therefore, the rasterization performance can be increased and the bandwidth is further saved than the conventional DF. As the simulation results using complex scenes, the memory bandwidth is reduced by up to 31% compared with the conventional pixel-level DF method