Sweep造型法在管线三维可视化中的应用

Application of Sweep modeling to 3D visualization of pipeline

管线三维可视化中的一个重要问题是如何根据管线中心线坐标计算得到管线表面顶点的坐标,难点在于管线转折处的表面处理。采用"sweep+mesh"的造型方法可生成整张连续的管道表面而不必在管线转折处做拼接处理。此方法通过在管线中心线各分段点上建立局部坐标系(标架),计算得到分段点对应的管线表面顶点的坐标,并生成连续的mesh网格。为建立连续的标架,提出了对管线进行倒圆角及分段处理,再递推生成标架的方法。结果表明:管线表面顶点坐标正确,整个表面光滑连续。

One of important problem in the field of 3D visualization of pipeline is how to calculate the coordinates of vertices on surface of pipeline by centerline coordinates and it is difficult to treat pipeline surface near turning point.The use of “sweep ＋ mesh” modeling method can generate the whole surface of the pipe without having to deal with issue of joining patches near turning point.Through establishing local coordinate system（frame） at sub-points on the center line of pipeline,vertices on surface correspond to sub-points can be calculated and generates mesh.To establish continuous frames,an approach to generate frames in recursive method after filleting and subdividing pipeline is presented.The results show that the coordinates of vertices on surface is correct,the entire surface is continuous and smooth.