Abstract
In this paper, we present a novel geometric method for efficiently and robustly computing intersections between a ray and a triangular Bézier patch defined over a triangular domain, called the hybrid clipping (HC) algorithm. If the ray pierces the patch only once, we locate the parametric value of the intersection to a smaller triangular domain, which is determined by pairs of lines and quadratic curves, by using a multi-degree reduction method. The triangular domain is iteratively clipped into a smaller one by combining a subdivision method, until the domain size reaches a prespecified threshold. When the ray intersects the patch more than once, Descartes’ rule of signs and a split step are required to isolate the intersection points. The algorithm can be proven to clip the triangular domain with a cubic convergence rate after an appropriate preprocessing procedure. The proposed algorithm has many attractive properties, such as the absence of an initial guess and insensitivity to small changes in coefficients of the original problem. Experiments have been conducted to illustrate the efficacy of our method in solving ray-triangular Bézier patch intersection problems.
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Project supported by the National Natural Science Foundation of China (Nos. 61100105, 61572020, and 61472332), the Natural Science Foundation of Fujian Province of China (No. 2015J01273), and the Fundamental Research Funds for the Central Universities, China (Nos. 20720150002 and 20720140520)
ORCID: Juan CAO, http://orcid.org/0000-0002-8154-4397
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Liu, Yh., Cao, J., Chen, Zg. et al. Ray-triangular Bézier patch intersection using hybrid clipping algorithm. Frontiers Inf Technol Electronic Eng 17, 1018–1030 (2016). https://doi.org/10.1631/FITEE.1500390
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DOI: https://doi.org/10.1631/FITEE.1500390