【摘要】 运用投影变换对两相贯曲面的求交进行降维降阶处理，将空间问题转化为较低阶次的平面问题，可以大大地简化求解斜插管两面角的算法，从而为在此类构件上正确开制焊缝坡口解决了一个难题．更多还原

【Abstract】 Applying projective transformation can reduce the object image to a lower dimension and reduce to a lower order when determining the intersection of two curved surfaces.Then the space problem translated into the planar problem in lower order. The dihedral angle between the oblique inserted pipes is calculated with great simplicity. That provided a easy and convenient method for machining weld groove with certain angle.更多还原