ImG-complex: graph data model for topology of unstructured meshes

Although, many applications use unstructured meshes, there is no specialized mesh database which supports storing and querying mesh data. Existing mesh libraries do not support declarative querying and are expensive to maintain. A mesh database can benefit the domains in several ways such as: declarative query language, ease of maintenance, etc. In this paper, we propose the Incidence multi-Graph Complex (ImG-Complex) data model for storing topological aspects of meshes in a database. ImG-Complex extends incidence graph (IG) model with multi-incidence information to represent a new object class which we call ImG-Complexes. We introduce optional and application-specific constraints to limit the ImG model to smaller object classes and validate mesh structures based on the modeled object class properties. We show how Neo4j graph database can be used to query mesh topology based on the (possibly constrained) ImG model. Finally, we experiment Neo4j and PostgreSQL performance on executing topological mesh queries.