The invention discloses a three-dimensional city modeling method based on BIM and GIS, comprising the following steps: data measurement,
data processing, establishing BIM model, establishing three-dimensional
GIS model, model fusion, municipal
simulation, element separation and optimization, model rendering and display; through BIM, the precise height of the building can be easily obtained, appearance size and
interior space information, thus through combining BIM and GIS, buildings are modeled first, and then the architectural spatial information is shared with the surrounding geographic environment, and applied to urban 3D GIS analysis, so that the cost of building spatial information can be reduced. At that same time, after the data is collected,
point cloud and aerial photograph data are calculated and simulated by
data classification comparison, so that the elevation information of the ground object is perfect, the elevation precision of the
building model is high, and the roof ismore fine. The invention does not need a large amount of manual interaction modeling, and the data are collected by the unmanned aerial vehicle and the unmanned vehicle, and the efficiency is high, the production period is short, and the timeliness is strong.