Three-dimensional (3D) CAD model lightweight scheme for large-scale assembly and simulation

Three-dimensional (3D) models are the most important carriers of CAD/CAE/CAPP/CAM, and usually they contain more information than practically needed as for some given applications, which may occupy superfluous storage space in computers. As a result, the handling speed also inevitably becomes slow, and certain inner secrets may be disclosed in the collaborative environment. The lightweight of large 3D models is an effectual solution. In this paper, a lightweight algorithm with intelligent information reduction for large-scale assembly is proposed to generate simple model by using their intrinsic structures. This algorithm aims at reducing the sizes of 3D CAD models within five steps and three levels from coarse to fine: components (including sub-assemblies and parts), feature and exterior geometry. Key strategies, such as components suppression, feature simplification and hollows seaming, are used in the processing. Finally, a shell model is created to represent the original one in subsequent applications. Different from 3D meshed model simplification, the proposed method is capable of reserving all necessary assembly interfaces for the further usage. Later experiments show that the lightweight method can obtain satisfactory results in practical design with preferable performance. The lightweight technology can be widely applied in many fields such as large-scale virtual assembly and movement simulation.