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A Memory-Efficient Unified Early Z-Test
September 2011 (vol. 17 no. 9)
pp. 1286-1294
Hong-Yun Kim, Korea Advanced Institute of Science and Technology, Daejeon
Chang-Hyo Yu, Samsung Electronics Co. Ltd., Yongin-City
Lee-Sup Kim, Korea Advanced Institute of Science and Technology, Daejeon
The Unified Early Z-Test (U-EZT) is proposed to examine the visibility of pixels during tile-based rasterization in a mobile 3D graphics processor. U-EZT combines the advantages of the Z-max and Z-min EZT algorithms: the Z-max algorithm is improved by the independently updatable z-max tiles and the use of mask bits; and the Z-min algorithm is improved by reusing the mask bits from the z-max test to update the z-min tiles after tile rasterizing. As a result, storage requirements are reduced to 3 bits per pixel, and simulations suggest that U-EZT requires 20 percent to 57 percent less memory bandwidth than previous EZT algorithms.

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Index Terms:
Computer graphics, graphics processors, visible line/surface algorithms, z-test.
Hong-Yun Kim, Chang-Hyo Yu, Lee-Sup Kim, "A Memory-Efficient Unified Early Z-Test," IEEE Transactions on Visualization and Computer Graphics, vol. 17, no. 9, pp. 1286-1294, Sept. 2011, doi:10.1109/TVCG.2010.228
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