Interactive Modeling Method For Urban Scene Simulation

With the rapid development of urbanization in recent years,the scale of cities is increasing,and different problems appear in the next step of urban planning.In this context,virtual city scene generation technology,which combines virtual reality technology and geographic information technology,has become a research hotspot.Study how to generate different objects quickly in urban scene,and then complete the layout of virtual scene model,which can not only assist urban planners to make decisions,but also provide help for traffic flow visualization,crowd evacuation simulation,game entertainment and other research in different fields,so this lesson has high application value and practical significance.This thesis investigates and analyzes the related work in the field of virtual city scene construction,studies the problems existing in the process of scene construction and puts forward corresponding optimization methods.Specifically,the main contents of this thesis are as follows:(1)This thesis analyzes the advantages and disadvantages of the existing methods for the structural description of overpasses,and proposes a structural description method of overpasses based on directed acyclic graph.On this basis,combined with the relevant standards of flyover design and construction,an algorithm for calculating the road height of flyovers is proposed and verified by experiments;(2)This thesis presents an interactive editing method of road model with auxiliary information.With the help of different auxiliary information,the adjustment of road height in three-dimensional space can be transformed into two-dimensional plane operation,which can effectively simplify the operation process and improve the accuracy of model editing;(3)A method of building layout constraint based on building code and collision detection is proposed.Combined with the building code and bounding box technology,the location of buildings placed by users in the scene is constrained,so as to improve the reality of the scene;this paper also constructs the urban building model library according to the type,height and style classification;(4)Based on unity3 d engine,a virtual urban scene construction system is designed and implemented.The system provides a friendly way of interaction,so that non professional users can also build a real virtual city scene in a short time;in addition,based on the virtual city scene design and implementation of two visual simulation examples,the application value of the research work in this thesis is verified.