Topology maintenance method based on three-dimensional geometric body combination

Abstract

The invention discloses a topology maintenance method based on three-dimensional geometric body combination, and the method comprises the steps: Boolean operation is performed on three-dimensional boundary surfaces, so that a relation surface set is obtained; geometric operation is performed on intersecting lines, so that a new edge is generated, and the relations between the lines and surfaces are updated; surfaces comprising crossing relation and containing relation are divided; all common elements and divide elements are combined, and the uniqueness of topology element is ensured; geometrical elements are combined, and new lines, surfaces and bodies are generated; and combined internal topological relation is updated. According to the invention, the method makes up a defect of inconsistent topological relation after spatial operation for three-dimensional body in a three-dimensional space; the construction of partial topological relation is accelerated through dividing the common surfaces and recording and combining the corresponding relations of front and rear elements; moreover, the method provided by the invention is suitable for combining operation between two bodies and complex space operation between a plurality of bodies.

Description

Technical field [0001] The invention belongs to the technical field of construction of topological relationships between geometric bodies in a three-dimensional space, and in particular relates to a method for maintaining a three-dimensional topological relationship based on a merge operation. Background technique [0002] Three-dimensional topological relationship is the most important spatial relationship in three-dimensional space, and it is the theoretical basis for three-dimensional spatial data expression, query, analysis and application. Brown (1988) expounded the importance of topology for scientific research in a general sense, and gave an intuitive idea of ​​proximity and continuity in a broad sense. One of the earliest examples of using topology to solve analytical problems was Euler’s study of the Koenigsberg Bridge in 1735. Topological relationship is of great significance to data processing and spatial analysis in three-dimensional space: 1) It can clearly reflect ...

AI Technical Summary

Problems solved by technology

[0004] The current research on 3D topology is basically limited to its formal expression and data model support, but there is no unified formal expression model and complete data model support that can cover all situations. The difficulty of topology construction is mainly reflected in the following aspects Points: (1) The formal expression model cannot describe all the situations of 3D topology well; (2) The logical data model can only partially support the construction of 3D topology, and cannot cover all of them, so as to realize the construction of the whole topology; (3) ) The production of data cannot be automated by computer, and the establishment of many data models requires manual intervention

In the existing 3D topology reconstruction research, the reconstruction of in vitro topology (the topological relationship between volumes) is often neglected. Many studies only focus on simple, regular, and consistent volumes, and the external topology is lost.

In addition, after the topology is constructed, splitting and merging are also a challenge to maintaining the topology. The new topological elements generated by splitting and merging need to maintain topology consistency with the existing topological elements.

At present, there are only a few studies on the construction of three-dimensional topological relations by Li Lin (2012), Guo Renzhong (2012), and even fewer studies on the maintenance of topological relations based on spatial operations

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