为了研究两平面相交可见性的规律，从空间一个平面的投影特点入手，将平面分别设定为正面、背面两面，讨论平面图形各顶点投影顺序与平面正面、背面的投影所具有的内在规律。

To study the intersection visibility of two general place planes, this paper set the planes as two faces of front and backs from the point of projection character of a space plane.

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