Research on 3D model and terrain matching method based on the segment of linear coordinates

At present, when the ultra-long linear 3D model is loaded in the 3D scene, it is difficult to adapt the ultra-long line model to the terrain model due to the influence of projection distortion. At present, some solutions mainly focus on the model rendering level, without considering the necessity of linear engineering construction, which is hard to encounter the requirements of 3D visualization in the meadow of linear engineering management. Therefore, this paper conducts research from two aspects of projection distortion calculation and analysis, linear engineering independent coordinate system establishment and so on, and puts forward the method of line model loading based on linear independent coordinate system piecewise technology. Firstly, the linear engineering projection distortion is calculated and analyzed. Then, based on the requirements of linear engineering construction accuracy, multiple independent coordinate systems that meet the accuracy requirements are constructed according to the characteristics of linear engineering. Finally, the 3D model of the ultra-long line is piecewise loaded, and the influence caused by the distortion of the projection length is apportioned through each independent coordinate system. The practical consequence indicate that this method can virtually optimize the difficult problem of model and terrain acclimatization caused by projection distortion, and meet the rendering requirements of linear engineering 3D models.