三维模型对称平面重建的特征匹配方法

提出一种利用实物对称特征重建对称基准平面的方法：首先选择一组对称特征；然后将测量数据点投影在一过测量坐标原点的平面——定义为初始平面上，并用折线连接，旋转初始平面使两条折线重合，可以得到一个与对称平面平行的平面；接下来再移动这个平行平面，使对称特征到它的距离相等，这时的位置平面即为所求的对称平面。该方法已在逆向工程数据前处理系统中实现，并应用于摩托车外形塑件的逆向工程．

Reconstructing Symmetry Plane by Feature Matching

The algorithm contains the following steps choose a couple of features with symmetry relationship which usually are boundary curves; fit the curves as B spline or polyline segments, then take the measured part central plane as an initial plane, and project the curves on to it, subsequently calculate the areas surrounded by the projected curves or the distance between them, there exists certainly one plane which makes the areas or distance minimum, the plane is defined as initial symmetry plane; again mirror two contours about the plane, translate the plane to make the distance of points to the contour minimum; finally an approximate symmetry plane can be got The technique is proved valid by practical applications and has been integrated with the current commercial CAD systems