Research Of Digital Inspection Used On Dimension Limit Of Railway Cargo With Opengl

The cargo loading states such as if the cargo' s outline intrude the railway gauge have great effect on the transportation safety of railway cargo. To simulate these effects, the program to simulate the inspection system of cargo loading safety has been developed on microcomputer by using Visual C++ MFC and OpenGL functions under the environment of MS Windows2000.The main research works in this thesis has been summed as following:1. A special program based on VC and OpenGL developing environment has been successfully set up. The program interface has interactive ability and the screen has been split into two parts: the left part used to display animation of three-dimensional geometric models and the right to user-interface of controlling.2. The geometric models are positioned and oriented in the three-dimensional space with a viewpoint easily to view the scene. A series of transformations functions of OpenGL such as matrix multiplication, include modeling, viewing, and projection operations. Such operations include rotation, translation, scaling, reflecting, orthographic projection, and perspective projection are provided to control the location of geometric models.3. The models reality has been increased by applying color, texture, hidden-surface removal, material and lighting. Hidden-surface removal is to eliminate the solid objects surfaces which are obscured by others. Texture mapping is to apply textures to points, lines, polygons, bitmaps, and images to improve the reality of models and decrease the procedure of drawing geometric models. A model' s material properties determine how it reflects light. Lighting has an effect when there are surfaces that absorb and reflect light.4. Different modes to draw geometric models are chosen according to the characteristic of models. If model shape is sample and regular,we use basic geometric primitives to draw. Otherwise complicated three-dimensional geometric model are created interactively in the software of 3DS Max and then transform it' s 3DS data structure into three-dimensional representation of entities with C/C++ language and store into display list by OpenGL.5. OpenGL provide double-buffering ability to complete animation operation. The cargo simulated animation and cross-section of cargo animation are processed synchronously. By blending and masking, image animation onto the screen without erasing what' s underneath another image are implemented.