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Enhancement of a multi-sided Bézier surface representation. (English) Zbl 1375.65032

Summary: A new multi-sided surfacing scheme – the Generalized Bézier (GB) patch – has been introduced recently by the first author et al. [“A multi-sided Bézier patch with a simple control structure”, Comput. Graph. Forum 35, No. 2, 307–317 (2016; doi:10.1111/cgf.12833)]. The patch is created over a polygonal domain, its parameterization is defined by means of generalized barycentric coordinates. It has a simple control structure; the control points are associated with a combination of bi-parametric Bernstein functions, multiplied by rational terms. GB patches are compatible with adjacent quadrilateral Bézier patches and inherit most of their properties.
In this paper we present an enhanced version of the former scheme. The control structure has been slightly modified, yielding a perfect generalization of quadrilateral patches. The parameterization has also been altered, matching a concept of how quadrilateral domains transform to \(n\)-sided polygons. We propose improved blending functions and investigate how the weight deficiency of the basis functions can be distributed amongst control points. The former rational weighting functions have been modified to support not only \(G^1\), but higher degree continuity between adjacent patches. After briefly discussing how degree reduction and elevation proceed, we present algorithms to automatically create and optimize the internal control points of GB patches. A few simple examples and suggestions for future work conclude the paper.

MSC:

65D17 Computer-aided design (modeling of curves and surfaces)
65D10 Numerical smoothing, curve fitting
Full Text: DOI

References:

[1] Ball, A. A.; Zheng, J., Degree elevation for \(n\)-sided surfaces, Comput. Aided Geom. Des., 18, 2, 135-147 (2001) · Zbl 0971.68168
[2] Floater, M. S., Generalized barycentric coordinates and applications, Acta Numer., 24, 161-214 (2015) · Zbl 1317.65065
[3] Hosaka, M.; Kimura, F., Non-four-sided patch expressions with control points, Comput. Aided Geom. Des., 1, 1, 75-86 (1984) · Zbl 0581.65009
[4] Kahmann, J., Continuity of curvature between adjacent Bézier patches, (Surfaces in Computer Aided Geometric Design (1983), North Holland), 65-75
[5] Krasauskas, R., Toric surface patches, Adv. Comput. Math., 17, 1, 89-113 (2002) · Zbl 0997.65027
[6] Loop, C. T.; DeRose, T. D., A multisided generalization of Bézier surfaces, ACM Trans. Graph., 8, 3, 204-234 (1989) · Zbl 0746.68097
[7] Pan, H.; Liu, Y.; Sheffer, A.; Vining, N.; Li, C.-J.; Wang, W., Flow aligned surfacing of curve networks, ACM Trans. Graph., 34, 4, 127 (2015) · Zbl 1334.68282
[8] Sabin, M., Non-rectangular surface patches suitable for inclusion in a B-spline surface, (EuroGraphics (1983), North Holland), 57-70
[9] Sabin, M., Some negative results in n-sided patches, Comput.-Aided Des., 18, 1, 38-44 (1986)
[10] Sun, L.-Y.; Zhu, C.-G., \(G^1\) continuity between toric surface patches, Comput. Aided Geom. Des., 35, 255-267 (2015) · Zbl 1417.65095
[11] Várady, T.; Salvi, P.; Karikó, G., A multi-sided Bézier patch with a simple control structure, Comput. Graph. Forum, 35, 2, 307-317 (2016)
[12] Wang, W.; Jüttler, B.; Zheng, D.; Liu, Y., Computation of rotation minimizing frames, ACM Trans. Graph., 27, 1, 2 (2008)
[13] Warren, J., Creating multisided rational Bézier surfaces using base points, ACM Trans. Graph., 11, 2, 127-139 (1992) · Zbl 0760.65019
[14] Zheng, J.; Ball, A. A., Control point surfaces over non-four-sided areas, Comput. Aided Geom. Des., 14, 9, 807-821 (1997) · Zbl 0897.65009
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