BRepQL: Query language for searching topological elements in B-rep models

Abstract

Topological elements form the basis for tasks such as geometric calculations, feature analysis, and direct modeling in 3D CAD systems. Handling these elements is also essential in various automated systems. This study proposes a method to search for topological elements within a boundary representation (B-rep) model by employing topological queries. To address complex scenarios that are difficult to handle using a single query, a topological query procedure that sequentially executes a predefined set of topological queries is used. To verify the effectiveness of the proposed method, experiments were conducted on Test Cases 1, 2, and 3, confirming the successful search of all target topological elements. Furthermore, tests on modified Snap-fit hook A and Bridge B models demonstrated that the same queries remained effective, provided the topological relationships and geometric constraints expressed in the query were preserved. In addition, a search time comparison showed that the proposed method reduced search time by over 90 % compared to manual processes. Finally, in an experiment involving participants with varying levels of programming proficiency, the results indicated that, for a developer with high programming skills, writing topological queries reduced the time required to search for a single topological element by more than 95 % compared to writing the program code.