Research On The Key Technology Of True Color 3D Terrain Solid Model By Rapid Prototyping

The 3D terrain solid model is a visual representation of geospatial information in the three-dimensional way,which can provide realistic,three-dimensional geography information for people to study the terrain,geomorphology and geospatial elements.However,due to its disadvantages,such as slow production and low precision,the traditional terrain solid model already unable to meet the modern society's requirements of real-time,accurate and efficient on mapping technology.With the rapid development of modern information and advanced manufacturing,CNC automation technology and rapid prototyping technology has been widely used in various fields of product manufacturing.In recent years,some researchers have made relevant researches on the application of advanced manufacturing and rapid prototyping technology in GIS field,which provides a solution for the production of high-precision and true-color 3D terrain solid model.Therefore,this paper discusses the key technology of rapid prototyping of True-color 3D Terrain Solid Model from the aspects of 3D terrain cartography synthesis,rapid prototyping method of terrain solid model,STL terrain model construction and precise matching of texture information.The main contents and results are as follows:(1)Based on the spatial autocorrelation feature of multi-scale DEM terrain factor,combined with the scale and forming accuracy of rapid prototyping of terrain model,the paper proposed a DEM terrain simplification method for rapid prototyping of terrain solid model.Through the analysis of the local autocorrelation of different terrain factors,the simplified DEM is constructed by selecting the terrain feature points according to the terrain characteristics corresponding to different significance.Experiments show that the method can keep the structural features and local details of the terrain in accordance with the application requirements of the terrain model,and solved the problems of that the terrain model surface is too fragmented and the geographical elements are not clear and disorganized.(2)By analyzing the data structure of DEM data and 3D printing data,the principle and related algorithm of building surface model with 3D surface cloud data are discussed.Then,the simplified DEM data is transformed into elevation point cloud data,and a triangular mesh of 3D terrain STL surface model is constructed.On the basis of the above,the 3D terrain STL surface model is further processed and optimized according to the model design requirements and the requirements of rapid prototyping to model data,and at last,the 3D terrain solid model based on DEM data is realized.(3)In order to evaluate the effect and practicality of the method,the rapid prototyping method of three true-color 3D terrain solid model is realized by combining different materials and different texture data.Firstly,based on the numerical control engraving and three-dimensional inkjet technology,an automatic production method of true-color terrain solid model is proposed,which realizes the effective matching of terrain model and texture information;Secondly,Based on 3D printing technology,a rapid prototyping method of true color terrain solid model is designed to accomplish the rapid prototyping of high precision and true color terrain model.The experimental results show that both methods can adapt to the rapid construction of high-precision terrain solid model and the effective matching of texture information,which greatly improved the accuracy of the model,and can expresses the structural features and geospatial information of terrain well.