线框模型投影图的消隐

Hidden line removal for wireframe projection drawing

不具有表面信息的三维线框模型投影到二维平面上,不能利用现有的立体投影消隐的方法来消除被遮挡线。提出利用包围盒与有向三角形相结合的方法,找出投影图中的相交边,通过投影模型计算距离并判断其相互的遮挡关系。引入遮挡矩阵存储遮挡信息弥补了投影降维后造成的深度信息损失。利用遮挡矩阵更新表示顶点间拓扑关系的连接矩阵,得到不含隐藏线的投影图。实验表明,算法稳定而高效。

Since Wireframe does not have the face information,the hidden line of its projection drawing cannot be removed by the existing methods.In this paper,an efficient algorithm for removing the hidden line from wireframe projection drawing was presented.In projection drawing,the intersection of the two lines was identified by bounding box and directed triangle.Further,the visibility of intersection lines could be determined by projection model.The occlusion matrix made up for the lost depth information during projection.The connected matrix of topological relationships between vertices was renewed by occlusion matrix,and the projection drawing defined by connected matrix had no hidden line.The test results show the high efficiency and stability of the proposed algorithm.