Visualizacion de terrenos mediante niveles de detalle

Resum

The interactive visualization of terrains is essential in GIS systems, virtual reality and simulators. This one creates some problems due to the large volume of information and to the need of reach sufficiently high speeds of refreshment to perform interactive animations. For the representation of terrains with different levels of resolution some models have been used: layers, sheltered and evolutionary. These models need a preprocesing time for the triangulation of the terrain before the visualization. Our work is inclided in the models sheltered, where the information about the triangulation of the terrain is stored in a tree with four children. The developed work consists of an environment that shows the terrains with different levels of detail. Firstable we take the cartographic model of heights and textures, that have the information of the terrain with the biggest resolution. Next we obtain the form of this terrain (the triangulation), according to some entry parameters: the orography of the area and the position of the camera. All results are obtained in real time, visualizing the area in the biggest resolution near the position of the camera and decreasing it in the places which are a long way from the camera. So we obtain a quickly visualization of the area because we don’t work with all the data. The triangulation of the area is obtained directly branching and bounding the tree in which all the information. The advantage of our model is that it don’t need any preprocesing time of the data, because they can be visualized directly. The environment of visualization, also incorporates the possibility of carry out virtual tours through some routes, which have been introduced by the user previously.