Research Of 3D Environment Management And The Design Of The Line Selection Of 3D Rapid Design System For Urban Rail Transit

The Urban Rail Transit Line is very important for the traffic diversion,project cost and the satisfaction of passenger.Most of the existing design methods of the Urban Rail Transit Line are based on topographic map and survey data in the two-dimensional design environment to alternate design the Plan with Profile and Cross-section.Nowadays,most of the Three-dimensional Graphics Library such as OpenGL and DirectX and other three-dimensional modeling software such as3 DMAX are used to construct a part of the model,which can not completely achieve the line design in the three-dimensional environment.There is no line design software which designs the line with the three-dimensional environment.In the 3D visual environment,through 3D browsing and analysis,Line interactive design will be very easy and visually to discover the potential conflict.What’s more,it not only facilitates to evaluate the design effect and the intelligent spatial analysis,but also conducts the removal of prediction,environmental impact assessment and landscape impact assessment.“The Research of 3D Environment Management and the Design of The Line Selection of 3D rapid design system for Urban Rail Transit”,is based on the idea of the line interactive design in the 3D visual environment,which studied the key contents of the administration and circuit design in the 3D visual environment.According to the theory,it form a set of methods and achieves it.The main research contents and results are as follows:(1)According to the characteristics of the 3D environment,we can determine the three-dimensional environment and set up the 3D development environment,which combines with the advantages and disadvantages of 3D graphics library.(2)According to the function of the 3D environment,the paper puts forward the changing view coordinate system,which based on the space position of the continuous transformation between the viewpoint and the object point.For the first time,the method is simple and practical,which can be used for 3D browsing in 3D graphics.(3)According to OpenTK graphic display process,it ensures the accuracy ofdrawing position by the matrix stack,which combines with coordinate systems and transformations.According to this principle,a new method is proposed,which is based on the combination mehods of Ray and Triangle Intersection and Inverse Coordinate Transformation.It could be fast and accurate to get the three-dimensional space point and provides the basis of the interactive design of the whole system.This method can achieve the function to query the spatial distance of the 3D environment.(4)According to the design standard and principle of the line design,which combines with the method of 3D point acquisition and 3D browsing technology,the rapid interactive design of urban rail transit line in the three-dimensional environment is achieved on the design principle of plane line and profile line.