{ "id": "1901.06885", "version": "v1", "published": "2019-01-21T11:33:25.000Z", "updated": "2019-01-21T11:33:25.000Z", "title": "B-spline-like bases for $C^2$ cubics on the Powell-Sabin 12-split", "authors": [ "Tom Lyche", "Georg Muntingh" ], "categories": [ "math.NA", "cs.CG" ], "abstract": "For spaces of constant, linear, and quadratic splines of maximal smoothness on the Powell-Sabin 12-split of a triangle, the so-called S-bases were recently introduced. These are simplex spline bases with B-spline-like properties on the 12-split of a single triangle, which are tied together across triangles in a B\\'ezier-like manner. In this paper we give a formal definition of an S-basis in terms of certain basic properties. We proceed to investigate the existence of S-bases for the aforementioned spaces and additionally the cubic case, resulting in an exhaustive list. From their nature as simplex splines, we derive simple differentiation and recurrence formulas to other S-bases. We establish a Marsden identity that gives rise to various quasi-interpolants and domain points forming an intuitive control net, in terms of which conditions for $C^0$-, $C^1$-, and $C^2$-smoothness are derived.", "revisions": [ { "version": "v1", "updated": "2019-01-21T11:33:25.000Z" } ], "analyses": { "subjects": [ "41A15", "65D07", "65D17" ], "keywords": [ "b-spline-like bases", "powell-sabin", "simplex spline bases", "maximal smoothness", "basic properties" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }