To reconstruct a model from such digitized scattered data you have to connect the sample points to get a surface approximation. So called Alpha-Shapes are often used for piecewise-linear approximation of dense scattered data. They are a generalization of the Convex-Hull and part of the Delaunay-Triangulation . They consist of points, lines, triangles and tetrahedra. To get a continuous differentiable (i.e. smooth) approximation of the object's surface the alpha shapes are split in several surface parts which are then replaced by polynomial patches. |