Study On 3D Terrain Model Visualization And Management Of Graphical Data In Forest Resource Management System Based On GIS Component

The purpose of this study is to illustrate the method that using OpenGL to realize 3D terrain visualization and using mapping software GIS components-MapObjects to manage graphical data of subcompartment on developing platform of Visual Basic.Terrain forest resource map provide the terrain information by contour, but it is difficult to read for laypeople. This study use OpenGL to realize 3D terrain visualization to help read Terrain forest resource map.In the Management of forest resource, the management of attribute data of subcompartment has developed into mature phrase, but the management of graphical data is weak. Nowdays, the "3s" technique become the effective way to manage spatial data of subcompartment. RS and GPS provide new data for GIS, while GIS provides the analyzing platform. The component GIS is becoming popular method in developing GIS program. It integrates GIS component with advanced programming language, such as Visual C++, Visual Basic, Delphi. It can take good use of programming language and GIS technique as well. MapObjects is one of perfect GIS components including many geo-functions, but they could not work before they are programming properly. Many functions have developed as following:1. Register Image function. Registering image is the first step to digitize map. The function provides convenient method to register image as the way in Arc/Info.2. Digitizing map.3. Forming feature from GPS data.4. Forming feature from compass data.5. Updatting geographical data automatically.6. Management of history data. It can review the situation in the past time.