Multirate Shading with Piecewise Interpolatory Approximation
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Date
2022
Journal Title
Journal ISSN
Volume Title
Publisher
The Eurographics Association and John Wiley & Sons Ltd.
Abstract
Evaluating shading functions on geometry surfaces dominates the rendering computation. A high-quality but time-consuming estimate is usually achieved with a dense sampling rate for pixels or sub-pixels. In this paper, we leverage sparsely sampled points on vertices of dynamically-generated subdivision surfaces to approximate the ground-truth shading signal by piecewise linear reconstruction. To control the introduced interpolation error at runtime, we analytically derive an Lā error bound and compute the optimal subdivision surfaces based on a user-specified error threshold. We apply our analysis on multiple shading functions including Lambertian, Blinn-Phong, Microfacet BRDF and also extend it to handle textures, yielding easy-to-compute formulas. To validate our derivation, we design a forward multirate shading algorithm powered by hardware tessellator that moves shading computation at pixels to the vertices of subdivision triangles on the fly. We show our approach significantly reduces the sampling rates on various test cases, reaching a speedup ratio of 134% ā¼ 283% compared to dense per-pixel shading in current graphics hardware.
Description
CCS Concepts: Computing methodologies ā Rendering
@article{10.1111:cgf.14674,
journal = {Computer Graphics Forum},
title = {{Multirate Shading with Piecewise Interpolatory Approximation}},
author = {Hu, Yiwei and Yuan, Yazhen and Wang, Rui and Yang, Zhuo and Bao, Hujun},
year = {2022},
publisher = {The Eurographics Association and John Wiley & Sons Ltd.},
ISSN = {1467-8659},
DOI = {10.1111/cgf.14674}
}