We present the construction of a suitable normalized B-spline representation for reduced Clough-Tocher splines. The basis functions have a local support, they are nonnegative, and they form a partition of unity. Geometrically, the problem can be interpreted as the determination of a set of triangles that must contain a specific set of points. This leads to a natural definition of tangent control triangles. We also consider a stable computation of the Bézier control net of the spline surface.Keywords : Clough-Tocher splines, normalized B-splines, control points, control triangles, Bézier control net MSC : Primary : 65D07, Secondary : 65D17, 68U07A normalized basis for reduced Clough-Tocher splines
Hendrik SpeleersDepartment of Computer Science, Katholieke Universiteit Leuven Celestijnenlaan 200A, B-3001 Leuven, Belgium
AbstractWe present the construction of a suitable normalized B-spline representation for reduced Clough-Tocher splines. The basis functions have a local support, they are nonnegative, and they form a partition of unity. Geometrically, the problem can be interpreted as the determination of a set of triangles that must contain a specific set of points. This leads to a natural definition of tangent control triangles. We also consider a stable computation of the Bézier control net of the spline surface.