Methodology of 3D underground object models and reality 3D models for urban information modeling (UIM)

This research introduces a method for developing urban information models (UIM) in the initial phase by extending the concept of building information modeling (BIM) in conjunction with photogrammetry. Utilizing data collected from aerial surveys using unmanned aerial vehicles (UAVs), with Naresuan University as a case study, the development is divided into two parts: 1) Development of BIM for underground structures, including water pipes, sewerage pipes, wastewater treatment systems, water storage tanks, and electrical and communication conduit systems; and 2) Development of realistic three-dimensional models for above-ground structures, especially focusing on old buildings lacking sufficient plans for BIM development. This involves aerial photography using UAVs, followed by computer software processing based on photogrammetry concepts and collaborative integration into a UIM. The research findings indicate that this approach can develop urban information models contingent upon the level of development (LOD) and level of information (LOI) specified in the model, as well as the definition of flight patterns and photography formats, while also considering certain challenges such as lighting and shadows.