针对正等轴测图3D重建中的隐藏元素求解，通过模拟人类的认知思维，提出了基于邻边推理求隐藏元素的算法。隐藏元素的推理就是通过对正等轴测图中含有隐藏边的点进行推理，根据其相邻边、过相邻点的边的方向和长度推理出可能的隐藏点集，然后根据重合性及连边规则对可能的隐藏点集进一步求解，得到隐藏元素的坐标信息和连边规则。深度推理算法就是用点的坐标信息和边的长度、角度信息推理每个点、边的深度。由C 工具和OpenGL技术开发的To3D验证了上述算法，证明该算法对平面立体的隐藏元素推理和重建十分有效。

In 3D model reconstruction from isometric drawing, it's a key step to reason the hidden elements. This paper proposes an algorithm to reason the hidden elements of the isometric drawing based on connected edges. Reason the hidden information is to reason through analysing these vertexes that have hidden edges, reason the direction and the length of connected edges and the edges that go through connected vertexes. After reasoning, we get some possible vertexes. Validating them with superposition and the edge circuits, we get the correct hidden element's coordinates and those circuits information.Then a method is introduced to seek the lost depth information based on the vertex's coordinates and those circuits information of the edges, its matrix is also brought forward. A prototype system To3D is developed using C and OpenGL tools to validate this method, the test result proves it's effective to reconstruct plan solid.