Oriented Rpm Point Cloud Data Directly Hierarchical Processing Technology And Its Software Implementation

This paper studies how to generate the slice data from point clouds, which is the critical problem in the integration of Reverse Engineering and Rapid Prototyping Manufacturing. At present, there are two ways available. In the firstpath, a CAD model is created first from point clouds then converted to a STL file. The STL file is then sliced to generate a series of layers for RP fabrication. The second path is to create the STL file directly from point clouds. However, there are drawbacks in these methods, such as long tune consumed, much manual interaction and so on.A new method is brought forward to solve this question. It goes directly from point clouds to a RP slice file. Three problems, the preprocess of point clouds, the method of directly slicing the point clouds, the extraction and fit of contour data, are discussed.This paper first expatiates the preprocess of data, which includes choosing the orientation to slice, topologizing the data, offsetting in the normal direction and smoothing the data. Secondly, it studies two ways of directly slicing, which is to generate the contour data on a series of parallel planes, or normal planes of a freeform curve. These two methods have the same principle, which gets the contour data by crossing the plane and the line between the two points of least distance. Finally, it addresses the process of contour data, such as extracting a cell-contour, sorting the points in one cell-contour to a contour line, and fitting the contour to a smooth one with biarc curves.