Research On Fine Model Of Building Based On 3D Rendering Technology And Close-range Photogrammetry

The development of smart city has proposed refinement requirement of simulation threedimensional city model. 3D refined model of city buildings, as the theme of city structure and the foundation of smart city, could survive city planning, management, emergency command and so on. And it has become an important technology through all the entire process. Lots of researches have been done in this direction, and researchers found that rely on traditional 3D modeling software only, such as 3ds Max, Maya, AutoCAD, Max, SketchUp and so on, unable to meet the requirements of accurate, rapid, efficient wisdom city construction. And the construction of wisdom city not only needs accurate geometric model, but also needs the real coordinate azimuth and texture information of vivid, real world and thus more real reaction.This paper presents a new method based on the combination of close range photogrammetry and 3ds Max professional modeling software to build the fine reconstruction of building, which aims to build fine model with both advantages. Context is based on the refined three-dimensional modeling of building, produced by close range photogrammetry aided three-dimensional modeling software for fine model, with fast and efficient production of fine three-dimensional model as the main target, based on the existing theory of threedimensional image reconstruction and technology. At the same time, this paper have ben done some explore and experiment in the three-dimensional mapping extraction, feature matching and texture mapping, which could assist 3ds Max using its strong point, line, surface editing function to produce fine model building. In the model of expression, for almost all the details characteristics including parapet, eaves corridor, the balcony, the window, the post, are fully expressed, the reconstruction of the complex building of high emulation degree model.Following aspects about these methods and results are introduced and focused in this paper including:(1) Firstly, this paper explored the modeling method of close range photogrammetry assisted 3ds Max, proved that the method which combines these two methods is feasible and effective through experiments. In addition, a method of constructing building fine model was presented from practice, at the same time, the basic technology and optimization method of fine 3D building model were proposed. The front part of paper introduced the model establishment method of the wall, form, and its subsidiary, hall door, balcony parapet, and other strongly designed components; and from the two aspects of ordinary texture and texture with alpha channel introduced methods of manufacture and mapping texture. When the 3D model was built after texture mapping, we carried on the optimized to model in order to provide convenient for users to roam or storage.(2) Building feature extraction. Feature extraction of image is one of the basic steps of 3D modeling essential, in this paper, line detection and vanishing points calculation was adapt to camera calibrate. Starting from the research targets, we knew that the purpose of calibration is not to seek the vanishing point, but calculated for inside and outside elements as the intermediate variable. In the aspect of feature extraction, replenished buildings structure line, form line, corner, the turning point and the regional characteristics and geometric constraints, to find the best correspondence points as well as the match lines, so as to provide basis for accurate to obtain the optimal texture unit.(3) In making texture unit, this paper combined close range photogrammetry with 3D modeling software, the point of combination is reflected in the production unit and 3D texture mapping. This paper used phi, omega, kappa and x0, y0, f calculated by camera calibration to texture unit extraction, generation and orthorectification method, and directly map texture from the above.In this paper, we chose the whole College of Life Science of Wuhan University as experimental area, verified the feasibility of the method proposed in this paper, and proved the advantages. It means that we no longer simply rely on modeling software itself, and reduced the manual intervention as far as possible; meanwhile, it can save cost, cheaper and more reliable than using of close range photogrammetry modeling method only. The two methods used alternately, gave full play to complementary advantages of both side, made it no longer be at a loss what to do for Building block section and its roof section. However, this method still has some limitations; experiments pointed at buildings which complexity not so high. For the strongly designed building, it has not been proved yet whether it is still has the above advantages.