Interactive Generation Of 3D Digital Virtual Terrain

With the rapid development of information and computer technology,the integration of computer graphics,multimedia,computer networks and artificial intelligence brings new opportunities and challenges to a lot of fields such as educational technology.The way that people used to know the world has been changed from flat-screen mode to three-dimensional mode.Its emergence and development bring a new experience and create a new vision to all people.As an important part of virtual reality,three-dimensional virtual terrain has been widely used in various fields such as computer aided design of clothing,machinery aided manufacturing,three-dimensional simulation of attractions and building models.Therefore,how to generate 3D models efficiently that can meet the design intents of users has been one of the most important research and application in human-computer interaction,and also been a hot topic in the field of 3D graphics modeling.On the basis of analyzing the existing terrain model generation algorithm,we put forward a kind of three-dimensional digital virtual terrain generation algorithm.Firstly,we definite a single-window rendering,multi-window view of user Interface and convert the curves by inverse projection method.Then users draw the terrain characteristic curve through a mouse click in the existing view window,including the ridge line and the boundary lines.Because the ridge line and the boundary line can represent key features of a terrain,drawing the two curves to define the terrain can simplify the operation of users,also can reduce the volume of data,and improve the efficiency of proceeding.Third,calculating terrain digital elevation model by using interpolate function.Because the terrain boundary line and the ridge are in the different spatial planes,before calculate the elevation values,we must determine the relationship between the ridge curve and the boundary curve.Therefore we use the method of projecting the boundary curve and ridge curve to the same interpolation plane to get the result.Forth,interactive generation of 3D digital terrain not only means generating terrain models but also requiring the ability of modifying and adjusting the terrain,we use the OpenGL pick-up mechanism to realize this process.The users achieve the purpose of local transformation and the interaction through the modification of those critical control points on the curves.Finally,add light and texture to the terrain surface to improve the realistic of it.The algorithm is simple,fast speed and it can complete the design and generate the terrain model interactively.