Parametric surfacelsurface intersection methods are essential in a sculptured solid modelingsystem- To improve the robustness, accuracy and topological consistence, an algorithm extendedfrom ideas in [1] and in [3] is...Parametric surfacelsurface intersection methods are essential in a sculptured solid modelingsystem- To improve the robustness, accuracy and topological consistence, an algorithm extendedfrom ideas in [1] and in [3] is described in this paper. Including a new rnethod for obtaining the sur-face near points; an appropriate method for estimating the marching step length; and a reliablernethod for determining singular points. Furthermore, our algorithm can evaluate intersections between offset surfaces without offset approximation. These ideas are discussed and implemented in anintegrated CADICAM system. Tested by rnany typical examples , they have been proved to be robustand efficient. Some exarnples are provided.展开更多
The new algorithms for finding B-Spline or Bezier curves and surfaces intersections using recursive subdivision techniques are presented, which use extrapolating acceleration technique, and have convergent precision o...The new algorithms for finding B-Spline or Bezier curves and surfaces intersections using recursive subdivision techniques are presented, which use extrapolating acceleration technique, and have convergent precision of order 2. Matrix method is used to subdivide the curves or surfaces which makes the subdivision more concise and intuitive. Dividing depths of Bezier curves and surfaces are used to subdivide the curves or surfaces adaptively Therefore the convergent precision and the computing efficiency of finding the intersections of curves and surfaces have been improved by the methods proposed in the paper.展开更多
文摘Parametric surfacelsurface intersection methods are essential in a sculptured solid modelingsystem- To improve the robustness, accuracy and topological consistence, an algorithm extendedfrom ideas in [1] and in [3] is described in this paper. Including a new rnethod for obtaining the sur-face near points; an appropriate method for estimating the marching step length; and a reliablernethod for determining singular points. Furthermore, our algorithm can evaluate intersections between offset surfaces without offset approximation. These ideas are discussed and implemented in anintegrated CADICAM system. Tested by rnany typical examples , they have been proved to be robustand efficient. Some exarnples are provided.
文摘The new algorithms for finding B-Spline or Bezier curves and surfaces intersections using recursive subdivision techniques are presented, which use extrapolating acceleration technique, and have convergent precision of order 2. Matrix method is used to subdivide the curves or surfaces which makes the subdivision more concise and intuitive. Dividing depths of Bezier curves and surfaces are used to subdivide the curves or surfaces adaptively Therefore the convergent precision and the computing efficiency of finding the intersections of curves and surfaces have been improved by the methods proposed in the paper.
