Research On Application Of Oblique Aerial Photography And3ds Max Plug-in Development In City Modeling

Currently, there are three ways for city modeling: modeling with3-dimensional software,modeling based on point cloud and aerial stereo pair. It is a traditional way to build city modelwith3-dimensional software such as3ds Max, AutoCAD and SketchUp, although it canmodel well in detail, it can not satisfy the need of rapid modeling in large scale scene. Formodeling based on laser scanning point cloud, although it has high level of automation, thereare some problems like hard processing of point cloud and the missing of texture information.And for aerial stereo pair, compared with others, it has advantages in cost, degree of coverageand level of automation, city modeling can be done based on the point cloud generated via thetechnology of image matching for aerial stereo pair or based on the line features extractedfrom the imagery, so the way of modeling based on aerial stereo pair is widely used in digitalcity building. In the process of texture reconstruction, however, it also encounters thephenomenons like the building block or blind side of shoot, which lower the speed and qualityof modeling. The most existed softwares which model using aerial stereo pair can only buildmodels of some buildings with simple architecture and have poor support on editing to modelobject, all of these limited the utility value of the software. Due to all of these limitations, thispaper presents a new approach based on the oblique aerial photography and3ds Max plugindevelopment for3D modeling.To facilitate discussing on the new approach, this paper also developed a measuring andmodeling platform for city modeling to prove the feasibility and practicality of the approach.The main content of this paper mainly focuses on four areas: research on the mode ofmeasurement and strategy of modeling; research on the algorithm and flow of the simpleconstruction modeling; research on the algorithm and flow of the complex constructionmodeling; research on the automatic acquisition and mapping of buildings’ textureinformation.(1) research on the mode of measurement and strategy of modelingDue to the enormous differences in buildings’ architecture, in this paper, a general flow ofmeasurement are designed and buildings are classified according to the architecture of roof tofacilitate the realization and modification for specific kinds of building.(2) research on the algorithm and flow of the simple construction modelingCombined with the powerful capabilities of modeling in3ds Max, the measuring andmodeling algorithm and flow for specific kinds of simple buildings are designed, such as thediscriminant algorithm based on the angle between the vectors and the nearest distance forsingle ridge house, the discriminant algorithm based on the visibility, the angle betweenvectors and the nearest distance for multiple ridge house. (3) research on the algorithm and flow of the complex construction modelingIn this paper, all kinds of constructions that can not be constructed by the modelingalgorithm of simple construction are classified to complex constructions, which have lots ofirregular line feature on their architecture, hence, based on the embed triangulation and3dsMax API, an network algorithm based on the visibility and polygon filling is presented in thepaper, and its utility and stability are verified by modeling experiment result.(4) research on the automatic acquisition and mapping of buildings’ texture informationCandidate imagery is picked out from oblique aerial imagery via location of texture andangle distinguishing, finally, the best one from candidate imagery is found by the choicealgorithm improved from other scholar’s thought; implementing texture minimum extractionby the smallest area rectangle; implementing textures mapping correctly by texturecoordinates allocation.