Research And Implementation Of Oblique Photogrammetry Data 3D Visualization Expression And Achieving Model To Be Single Based On NewMap World

Achieving the separate 3D building model to be single refers to each object that is to be managed and analyzed separately.Achieving the separate 3D building model to be single based on oblique photogrammetry image is to separate the three-dimensional model that needs to be analyzed separately from other 3D models.So that it can be managed and analyzed separately,rather than just being used to view.Oblique photogrammetry data is handled by professional tools.Its product is oblique photography 3D model.The process is automatic.Firstly,a thick point cloud is generated by the oblique photogrammetry image taken by the camera.Then the point cloud is sparse,and then the triangulation network is constructed.Finally texture mapping is completed according to different regions on the 3D models and thus the 3D models are generated.The data processing needs no manual works.The current modeling algorithm does not take buildings,ground,wood and other features to distinguish.Thus built is a continuous irregular triangle net.Such data itself are not separate to a single building or selected.The data need for further processing to achieving the separate 3D building model to be single.With the rapid development of society,people have higher demands.Today’s three-dimensional geographic information system is no longer limited to just to look at effects or only used in emulate.For most applications need to be able to separate the 3D architectural features,such as model analysis.And the abilities of setting some properties on these 3D models and query attributes form them.The basis for these functional implementation is separating 3D building model.These are typically very basic capabilities of geographic information system.Therefore,achieving the separate 3D building model to be single becomes the important problem that will solve in the oblique photogrammetry image applications.According to different principles of achieving the separate 3D building model to be single,it can be divided into cutting way and uncut way.Uncut way just give observer different experience in visual effect.But there is no separation,so it is not completely separate 3D building model to be single.The main advantage of cutting way is achieving the separate 3D building model to be single.The existing method of cutting way is based on point set.Its model edge effect is poorer.In this reason the cutting way is adopted.The cutting way will improve the 3D model’s edge,which needs separate 3D building model to be single.The model’s edge will be consistent with the screen resolution.The splitting property of triangle patches are used to solve the problem of achieving the separate 3D building model to be single based on oblique photogrammetry image.Firstly,draws a cutting polygon to get the model boundary.Then use bounding box to make the intersection detection to obtain the triangle patches which need to be cut.And to find intersection points of triangles which may intersect with cutting polygon.Each of intersecting cases is detailed introduced and analyzed.All these intersection should be cut according to their actual conditions respectively.The cut triangular patches should be reconstructed.Through reconstructing the texture can achieve the separate 3D building model to be single.The empirical results strong support separable monomer efficiency of the method.