Tnt. Goodman et J. Peters, BEZIER NETS, CONVEXITY AND SUBDIVISION ON HIGHER-DIMENSIONAL SIMPLICES, Computer aided geometric design, 12(1), 1995, pp. 53-65
Explicit necessary and sufficient conditions for the convexity of a mu
ltivariate Bezier net are given. These are used to show that the Berns
tein polynomial of a function on a simplex preserves a strong form of
convexity, that takes the generating directions of the simplex into ac
count. Moreover, an efficient algorithm is presented for computing the
Bezier points on a regular subdivision of a simplex in higher dimensi
ons. This subdivision process preserves the convexity of the Bezier ne
t.