Implementation of weather

VWorldTerrain includes a weather management system module called DWS (Dynamic Weather System). After processing the three following meteorological databases:

- Cloud cover
- Wind speed and direction
- Ground level temperatures

The DWS allows to read and integrate in real-time the resulting processed data. There is a file for each month of the year; data are procedurally interpolated each month after the other, which results in a real-time management of weather (information contained in these meteorological files can thus be rendered to the millisecond). At a given “t” time three parameters are therefore extracted from these three databases, and are procedurally retranscribed; the DWS then gives specific indications as to weather conditions for a given location (while of course also taking DEM and LandCover data into consideration)


No clouds, average temperatures, no wind: a beautiful day No clouds, high temperatures, very windy: a sandstorm in the desert Very cloudy, temperatures below zero, no wind: let’s go skiing! Very cloudy, medium high temperatures, no wind: stormy weather The DWS’s main asset not only lies in a very realistic rendering of weather phenomena but also in the system’s ability to replay the selfsame phenomena at a given place and time. That is to say several computers will be able to display the very same weather conditions without necessarily being on a network: the only variable in all calculations is time (expressed in milliseconds).

Besides, elements of the scenery are affected by weather condition changes (cloud cover + wind):
- wind (speed and direction) has an impact on the way clouds are moving, on the way rain or snow is falling, on ground materials (snow and sand), on objects ( trees, flags…) - the colour of the sky varies according to temperatures; under certain circumstances, mist, or fog, is forming. The snow mantle is thinner or thicker, depending on weather conditions. Also, depending on the relief and if rain is falling down heavily or not, water puddles may appear. Thanks to the DWS, the Eingana Act I and I.5 software featured a very realistic management of seasons system on the entire surface of the Earth.