三轴数控铣床系统图形的实时显示

在三角网格模型的基础上，提出一种数控铣床系统中刀具扫描体的快速求法，充分利用计算机图形学中直线和圆弧域的求交方法——中点求交法和四向圆弧填充法，变浮点乘除运算为有利于计算机硬件实现的整数加减运算；并提出了操作方便的三角网格简化LOD方法，在图形显示时，该方法根据图形显示比例系数，把在一个像素范围内的小三角片合并成大三角片；对用LOD方法简化后的非特征区法矢相同的大三角片面进行进一步合并．实验结果表明，上述方法减少了图形显示时的运算时间，提高了图形显示速度及效率．

Real Time Graphics Display of Milling Motion in Three-axes NC Machining

Based on triangular mesh model, A simple rapid method for swept volume of milling cutter moving in NC machining is presented. By utilizing the middle point line and 4-connected circle fill algorithm in the calculation of line-circle intersection, this method converts the multiplication?division operations into additions?subtractions. Additionally, an easily realized LOD (Level of Detail) scheme for reduction of triangles is also presented. By the scheme, the triangles in one pixel are combined into bigger ones according to the coefficient of graphics display scale and then the triangles that have equal normal in non-characteristic sections are also combined. Experiments show that the efficiency of graphics display is improved greatly.