Bi-3 C 2 polar subdivision

Autor: Ashish Myles, Jörg Peters
Rok vydání: 2009
Předmět:
Zdroj: ACM Transactions on Graphics. 28:1-12
ISSN: 1557-7368
0730-0301
DOI: 10.1145/1531326.1531354
Popis: Popular subdivision algorithms like Catmull-Clark and Loop are C 2 almost everywhere, but suffer from shape artifacts and reduced smoothness exactly near the so-called "extraordinary vertices" that motivate their use. Subdivision theory explains that inherently, for standard stationary subdivision algorithms, curvature-continuity and the ability to model all quadratic shapes requires a degree of at least bi-6. The existence of a simple-to-implement C 2 subdivision algorithm generating surfaces of good shape and piecewise degree bi-3 in the polar setting is therefore a welcome surprise. This paper presents such an algorithm, the underlying insights, and a detailed analysis. In bi-3 C 2 polar subdivision the weights depend, as in standard schemes, only on the valence, but the valence at one central polar vertex increases to match Catmull-Clark-refinement.
Databáze: OpenAIRE