Ancient Chinese timber architecture, with its complex structural system and long historical continuity, holds significant cultural and academic value. 3D semantic modeling enables semantic-based querying, analysis, and visualization, serving as a foundation for heritage digitization and conservation. However, existing data models lack the capability to represent the class and component characteristics of traditional timber buildings, constraining data integration and GIS-based applications. This study develops a CityGML-based Application Domain Extension (CTAADE) for the semantic 3D representation of traditional Chinese timber architecture. By extending CityGML 2.0 modules, CTAADE introduces domain-specific classes and properties, achieving integrated representation of geometry and semantics. A case study of the Great Compassion Hall at Chongshan Temple in Taiyuan demonstrates that CTAADE effectively integrates geometric, attribute, and semantic information for semantic-driven 3D modeling. This research provides a technical pathway for digital documentation and preservation of Chinese timber heritage and establishes a foundation for integration between heritage science and GIS.
Zhang et al. (Tue,) studied this question.