3D visualization tool for Virtual models of natural disasters Eva Pajorová, Ladislav Hluchý, Ladislav Halada, Peter Slížik Institute of Informatics, Slovak Academy of Sciences Dúbravská cesta 9, 84507 Bratislava, Slovakia eva.pajorova@savba.sk hluchy.ui@savba.sk ,upsyhala@savba.sk , peter.slizik@savba.sk Abstract Visualization of large realistic forests, various countries, floods, fire spreads and landslides is very difficult and requires using of perfect modern graphic methods which allow rendering them as scenes in real time. This paper describes the creation of 3D visualization tool for visualization of natural disasters. A lot of international projects oriented on natural disasters utilise grid computing and within grid solution raises requirement of visualization service for presentation of the results. Such service requires unified standards like integration of input data formats and especially creation of unified visualization tool. It should integrate visualization requests of any kind of application oriented on computing of natural disasters. In case it is grid computing it has to be established also submit workflow, which controls execution of this visualization service. Development of all executable modules and solution of all above mentioned grid computing specific problems was subject of our scientific work presented in this article. The 3D visualization tool as well as submit workflow were tested on the applications solved in project MEDIGRID and on natural disasters applications solved in our institute [12]. Keywords 3D visualization tool, virtual reality, natural disasters, fire, flood Introduction The natural disasters like fires, floods and landslides become subject of science in research institutions more and more frequently. Topic of a lot of projects is how to prevent such disasters. Many applications from this area are using different kinds of simulation tools, which are producing output data for displaying the results of the computation. The purpose of 3D visualization tool is to display results of various simulations of natural disasters like fire spread in time, its intensity and erosion or floods in time or landslides as well. The output of the tool is terrain covered by ortophotomap or it is only shaded according to the altitude. On such prepared terrain is displayed the simulation of the fire spread in time, its intensity and erosion, flood water spread in time and so on. They are visualized statically or dynamically by adding red faces for the fire, blue faces for the water and brown faces for the landslides. Output of the tool can also be the files representing the virtual reality of natural disaster. For example in case of fire the spreading red faces are replaced by virtual fire. Similarly in case of flood the blue faces are replaced by virtual water and so on. 3D visualization tool was tested by output from applications, which were solved in our institute and also by data from applications in project MEDIGRID. Particular demonstrations in this article are from fire in part near Mediterranean Sea at south. Exactly in Marseille industrial port at south east. The second is from large fire in Krompla region, which is part of Slovensky Raj. Flood demonstrations are from Povazie, the region around the river Vah. The tool is always actualised according to the needs of new applications. Related work There are several tools solving the visualization of natural disasters. However, these tools lack common criteria for visualizations, unification of data formats, and a common approach to visualisation. The integration of formats and a common solution for visualization of natural disasters, which has been solved in our tool, provided the opportunity to create a visualization service for grid applications aimed to natural disasters. As the applications computing natural disasters work with big amounts of data, grid computing is used frequently. Using a 3D visualization tool in a grid visualization service could be considered a big contribution. This has been proved by increasing interest of experts working on international projects. Searching for new facilities of preventing natural hazards, they are continually seeking to integrate the existing applications. One of them is the visualization service with it’s submit workflow. Creating 3D visualization tool 3D visualization tool consists of modules which was necessary to create. Each module is UNIX shell script in which is prepared starting of executables. The modules are divided into three