The Research And Implementation Of3D Terrain Automatic Generation Technology

The three-dimensional electronic map seems to have more advantages than thetwo-dimension electronic map in information contained, the ways of expression andreality, therefore, the three-dimensional electronic map has high application value. TheThree-dimensional electronic map’s main task is to establish and manage theThree-dimensional terrain. In this paper, we provide a technology of automaticalgenerating three-dimensional terrains. We also use the database to manage multiplethree-dimensional terrains, and finally establish a simulation program which proves thefeasibility and effectiveness of the Three-dimensional deep-sea terrain and the database.In this paper, we first deeply research the method to extract and process the deep-sea data.On this basis, we design and realize a program for extracting the depth in two-dimensionalelectronic charts. Deep-sea data obtain by reading the two-dimensional electronic charts hadfewer data points in a large range, therefore the data should be interpolated.This paperexplains the algorithm of processing deep-sea data, and designs and realizes a program forprocessing deep-sea data with the IFS fractal interpolation algorithm. The program processingdeep-sea data of three-dimensional terrain stores the data into a three-dimensional surface file(. bin file).This paper proposes a method to turn three-dimensional surface file intoThree-dimensional terrain file with Creator, introduces and analyses various kinds ofsubdivision algorithms in detail. Generated three-dimensional terrain files can be a verysatisfy performance of the elevation information of terrain, but it can not reflect the substrateinformation of terrain. Thus, we should render terrain files.The traditional rendering methodsneeds a lot of workload and has some randomness.This paper provides the automatedrendering tools and explains its process of designing and realizing.The management of three-dimensional depth-sea terrain is mainly to solve two problems.1. The three-dimensional terrain charts needs to switch terrains, then how to get thethree-dimensional terrain which is need to load into memory is an issue in front of us.2. TheThree-dimensional deep-sea terrain accounts for a large memory and it is slow to retrieve datain the single terrain. For the first problem, this paper designs a database table based oncross-linked structure. So we can speed up the process of searching terrains when we need toswitch terrains.For the second problem, we designs a hierarchical table structure of thedatabase to store a single three-dimensional terrain. This paper also explains the design process of the table structure in three-dimensional terrain database. We design and implementan automatical tool for importing three-dimensional terrains, and show the software’s processof designing.At last, the paper applies a simulation program to test the three-dimensional terrain’savailability and the effectiveness of database. We explain the design and the implementationprocess of simulation program. And the availability of terrain and the effectiveness ofdatabase is proved by two kinds of roaming.