The Method And Implementation Of Topology Checking And Editing Of 3D Spatial Objects

In daily life,the geographical entities seen by people all exist in the form of 3D,however,most of the researches in the traditional GIS applieation field are to project the 3D geographieal entities to the 2d plane and transform them into 2d angles to describe problems.Three-dimensional GIS overcomes the limitations of traditional GIS,such as the difficulty in expressing the authenticity of ground objects,and the geographic entity inforration it expresses is close to the geographical entity people see in the real world.In recent years,3D GIS has been more and more accepted and understood by people,and has become a hotspot and diffieulty in GIS research.With the rapid development of the Internet,Web 3DGIS technology is formed by the combination of 3DGIS and Web technology.Web 3DGIS can use the Internet to publish and share 3D spatial data,which greatly promotes the development of GIS industrialization and popularization.The 3D solid model in Web 3DGIS can be used to construct the geographical entity close to the real world,and the visual effect of the user is more real.When people browse the 3D scene in the browser interface,they can have an immersive experience.Topological relation is the most important spatial relation,and is the key research direction in the field of constructing three-dimensional physical model.It can visually reflect the logical structure relationship between spatial objects.Topological relation can be used to set up spatial data model,query spatial data,publish spatial data and so on.According to the topological relation among geographical entities,spatial objects with topological errors can be determined,and then these spatial objects can be edited.1.Research on spatial data model,the use of relational database according to the space vector data structure model based on the storage format of different data table used to save point,line,face,body and other space objects,in order to efficiently for spatial data read and storage.2.By means of Euler's formula and minimum bounding box method,various topological relations among spatial objects are studied carefully to form the methods of querying the topological redundant data of spatial objects,determining topological errors,modifying topological errors,etc.It aims to complete the algorithm of checking and editing the topology of three-dimensional spatial objects and write code.Then realize the function of checking and editing the topology of 3D objects.3.Using JavaScript scripting language and VRML virtual modeling language to realize the spatial object in three-dimensional scene shows on the web interface and topology errors.This paper takes the construction of a building's three-dimensional model as the research object,with the help of ASP.NET technology,compiles the code of the three-dimensional spatial redundant object decision function.It also completes the system design according to the object-oriented idea,and then realizes the topology checking and editing of the three-dimensional spatial object,hoping to provide some reference for the future research of spatial topology query and operation.Fig[18]Table[4]References[52]...