摘要
采用在曲面的参数域上均匀分布矩形网格的方法，把ｔｒｉｍ ｍ ｅｄ ＮＵＲＢＳ曲面的三角化问题，转化为对每个含在有效参数域内的矩形网格区域中的三角化处理，以及对裁剪边界和与其相交的矩形网格围成区域的三角化处理。该方法运行速度快，适用于法曲率变化不大的ｔｒｉｍ ｍ ｅｄＮＵＲＢＳ曲面的真实感图形实时显示。
From the viewpoint of improving the quality of triangle facets and decreasing triangulation speed, a highly efficient tessellation algorithm for a trimmed NURBS surface is presented. By uniformly spacing rectangular grids over the [0,1]×[0,1] normal parameter region of the parametrically defined surface, the triangulation of a trimmed NURBS surface is implemented through faceting rectangular grids which are either in or across the valid parameter region of the trimmed NURBS surface. The longest side length of a triangle and grid numbers in u,v directions over the parameter region is computed in terms of a tolerance formula for the NURBS surface. The three dimensional triangulation result is obtained by mapping the triangle facets on the valid parameter region of the trimmed NURBS surface. For the rapidity and simplicity of the triangulation algorithm, it is very suitable to display in real time a realistic image of the trimmed NURBS surface with gently varying normal curvature.
出处
《南京航空航天大学学报》
EI
CAS
CSCD
北大核心
1999年第5期569-574,共6页
Journal of Nanjing University of Aeronautics & Astronautics
