Abstract: In the literature of computer-aided conceptual design and computer graphics, the 3D
reconstruction of geometric solids from single 2D line drawings provides the user an easy way for
efficiently generating new complex objects. According to a user input 2D line drawings that may
include not only straight sketch lines but also sketch curves, an efficient and convenient reconstruction
approach of 3D complex mechanical objects is presented in this paper that may contain the ribbon-like
faces, inner cylindrical faces and hollow polygonal faces, etc. Due to the pre-defined assumption that
the given 2D line drawings is a single parallel projection of 3D shapes, our reconstruction technique
firstly introduces a series of input rules for efficiently interpreting the user input 2D line drawings and
thus recognizing the topological structure of the geometric solids. Then, the algorithm computes the
accurate 3D coordinate information of vertices by using cubic corner theory. Based on the user specified
topological information of 2D line drawings, the complex mechanical objects are finally reconstructed
and represented as triangular meshes. Experimental results demonstrate that our reconstruction scheme
can efficiently generate the comparatively complex geometric solids in a deterministic manner,
especially for 3D complex mechanical objects.

Key words: 3D reconstruction, 2D line drawings, complex mechanical objects, cubic corner