DTGBrepGen: A Novel B-rep Generative Model through Decoupling Topology and Geometry
This work addresses a domain-specific problem in Computer-Aided Design by improving the generation of B-rep models, which is incremental as it builds on prior methods by explicitly handling topological constraints.
The paper tackles the challenge of automatically generating valid and high-quality boundary representation (B-rep) models in CAD by proposing DTGBrepGen, a framework that decouples topology and geometry generation, resulting in significantly higher validity rates and more diverse, realistic outputs compared to existing methods.
Boundary representation (B-rep) of geometric models is a fundamental format in Computer-Aided Design (CAD). However, automatically generating valid and high-quality B-rep models remains challenging due to the complex interdependence between the topology and geometry of the models. Existing methods tend to prioritize geometric representation while giving insufficient attention to topological constraints, making it difficult to maintain structural validity and geometric accuracy. In this paper, we propose DTGBrepGen, a novel topology-geometry decoupled framework for B-rep generation that explicitly addresses both aspects. Our approach first generates valid topological structures through a two-stage process that independently models edge-face and edge-vertex adjacency relationships. Subsequently, we employ Transformer-based diffusion models for sequential geometry generation, progressively generating vertex coordinates, followed by edge geometries and face geometries which are represented as B-splines. Extensive experiments on diverse CAD datasets show that DTGBrepGen significantly outperforms existing methods in both topological validity and geometric accuracy, achieving higher validity rates and producing more diverse and realistic B-reps. Our code is publicly available at https://github.com/jinli99/DTGBrepGen.