Geometric conditions of non-self-intersecting NURBS surfaces

Representing rational curve segments and surface patches using semi-algebraic sets

“…Surface patches without singular points are popular in geometric modeling and there are methods to design surface patches without singular points by checking certain geometric conditions (Zhao and Zhu, 2015;Zhao et al, 2017). For a surface patch without singular points, we can find a semi-algebraic set for the patch.…”