1、VIRTUAL REALITY MODEL OF AIR POLLUTION M. Mudrova, A. Prochazka, and M. Kolnova Institute of Chemical Technology, Department of Computing and Control Engineering Abstract The paper is devoted to the description of virtual reality model generation using the system Matlab and its Virtual Reality Toolb
2、ox. The selected possibilities of interconnection of both systems (Matlab and VRML) are demonstrated by means of visualisation of two-dimensional interpolation of air pollution data. 1 Introduction Presentation of three-dimensional data currently represents a very topical theme in many areas, and no
3、t only technical ones. Clear and intelligible arrangements of information in the 3D model is necessary for example in medicine and it is used more and more frequently in other areas. Results of information processing using complex mathematical tools can naturally lead to formulation of a three-dimen
4、sional graphical model. It has been possible to observe or process spatial data for all users of personal computers since the VRML (Virtual Reality Modeling Language) had been developed 5, 6, 7. The most frequently used Internet browsers (MS Internet Explorer and Netscape Navigator) have a VRML view
5、er built in. There are also many other freeware plug-in modules available on the Internet with which one can enter the virtual world and observe it and possibly control it as well. Thanks to these facts, it is expected that areas of applications of 3D modeling will grow. The goal of this paper is to
6、 describe the process of formulation of a 3D model of air pollution level in the Czech Republic using the system Matlab, and its export to VRML. 2 Background The virtual realistic scene establishes to generally have two kinds of paths: Adopting openGL, VRML， Direct 3D is the 1st。 For non-calculator
7、professional personnel to say, make use of OpenGL to write a complicated 3D application doubtless is a challenge. VRML language oneself writing is very easy, but this kind of language function be weaker, and it seems to be to lack the ability to do in the aspects of handle complicatedly progress, wi
8、th other high classic language of the conjunction be also not enough convenience. Direct 3Ds are a 3D sketch plait distance API that the Microsoft companies release, it mainly applied at the plait distance of 3D game, needed to weave a distance a personnel to have higher ability of C+. High language
9、 of plait distance achievement bottom, as a result is also hard and universal. Therefore establish a virtual realistic scene to need to there is better plait distance through this kind of path ability, need to acquaint with a certain language in the meantime, suitable for professional development pe
10、rsonnel；The 2nd method is to adopt a certain and virtual realistic environment to establish tool to establish, this kind of tool provides a valid path which averts from process and language norm of the complications plait distance to establish a virtual realistic scene for the customer according to
11、a certain language and the development terrace, this tool has already have currently some experiment system is report?And the majority be according to the VRML. But regardless according to which terrace, see still not mature from the technique, there being still more problems should be resolved. 3 R
12、eal Data Description Automation Imission Monitoring System (AIM) in the Czech Republic that includes more than 100 measuring stations 3 provides regular measurements of chosen components in the air. Con-centrations of selected pollutants are measured at every station in 30 minute intervals during th
13、e whole year. These data allow to watch the air pollution level at exactly located points, and by using interpolation methods, in the whole area of the Czech Republic, as well. Graphically presented results of interpolation make the imagination faster and clearer. They could be also compared with pa
14、rallelly performed NOAA (The National Oceanic and Atmospheric Adminis-tration) satellite observations and namely concentrations of dust particles in the air. The one years time series representing current concentrations of the PM10 pollution obtained from the AIM stations has been kindly provided by
15、 the Czech Hydrometeorological Institute in Prague. The data observed at locations presented in Fig. 1 were preprocessed by means of compensation for values of measurement failures and elimination of distant values 4. Figure 1: The AIM station layout in the Czech Republic with marked Delaunay triang
16、ulation 4 Two Dimensional Interpolation Methods It is possible to use various interpolation methods for estimation of values of an observed pollutant in other non-measured points specied by a selected orthogonal net. The description and comparison of these problems has been presented in 4. It is pos
17、sible to use the simplest method of the 0-th order - the nearest neighbour method that interpolates the surroundings of a given station by the same value measured in the station. Voronoi diagrams 1 limit the surrounding borders. Related Delaunay triangulation method presented in Fig. 1 is used for higher-order interpolation (bilinear, cubic, spline). A selected method applied to the array of calculated concentrations values results in the orthogonal net de_ning longitude and latitude. The three-dimensional model represents a natural presentation of these results.
