Quasi-Linear Depth Buffers With Variable Resolution
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Date
2001
Journal Title
Journal ISSN
Volume Title
Publisher
The Eurographics Association
Abstract
In this paper we present new class of variable-resolution depth buffers, providing a flexible trade-off between depth precision in the distant areas of the view volume and performance. These depth buffers can be implemented using linear or quasi-linear mapping function of the distance to the camera to the depth in the screens pace. In particular, the complementary Z buffer algorithm combines simplicity of implementation with significant bandwidth savings. A variable-resolution depth buffer saves bandwidth by changing size of the per-pixel depth access from 24 bits to 16 bits when distance to the pixel from the camera becomes larger than a given threshold, This distance is selected in order to keep the resulting resolution equal or larger than the resolution of the 24-bit screen Z buffer. For dynamic ratios of the distances between far and near planes 500 and above, bandwidth savings may exceed 20%. Quasi-linear depth floating-point depth buffers are best at high dynamic ratios; 3D hardware should support per-frame setting of the optimal depth buffer type and format. Per-frame adjustment of the resolution switch distance allows balancing performance with depth precision and should be exposed in the graphics A PI.
Description
@inproceedings{:10.2312/EGGH/EGGH01/081-086,
booktitle = {Eurographics/SIGGRAPH Graphics Hardware Workshop 2001},
editor = {Kurt Akeley and Ulrich Neumann},
title = {{Quasi-Linear Depth Buffers With Variable Resolution}},
author = {Lapidous, Eugene and Jiao, Guofang and Zhang, Jianbo and Wilson, Timothy},
year = {2001},
publisher = {The Eurographics Association},
ISSN = {1727-3471},
ISBN = {158113407X},
DOI = {/10.2312/EGGH/EGGH01/081-086}
}