MapView – interactive off-screen visualization on Google Maps data
MapView is a collaborative project that has been created by Judith Junge, Lisa Wertig and myself as part of a project for our “information visualization” course at the Otto-von-Guericke University, Magdeburg. MapView has been created to visualize geographical locations on an interactive map with special focus on visualizing objects that are outside the current visible screen area. This is essential for navigation and becomes more and more important as devices and screen sizes get smaller and handheld navigation devices such as smartphones and car navigation become more popular.
One important aspect when creating the software was to keep the software usable in a manifold variety of use cases, so it was essential for us to implement an interactive map that provides multiple detail levels and worldwide map data. And since most geographical locations are determined by latitude and longitude values we needed to find a way to map geographical locations to the xy-based coordinate system that is used by Qt frameworks drawing libraries.
To achieve this the Google Maps API was ideal for us. It allows including map data from all over the world in a huge variety of detail levels and even support for satellite data or other image data. So we implemented a QGraphicsView that basically just loads a website in a QGraphicsWebView. This allows us to embed map data into a graphics scene and render any other object on top of it.
Mapping the geographical locations to the graphics view coordinate system was a problem at first, since this would have caused quite a bit of calculations. But to solve this problem the Google Maps API came in handy again, since it provides mapping functions to get x/y-coordinates out of geo-referenced data. Having this we were able to render any object on any geographical location on top of our map data.
Main goal for the software was to implement several different visualization methods that encode the position, direction and distance to objects that are not visible in the current window. For this we implemented several different algorithm, such as the “halos”, the “arrows” and “wedges”. Each one has different advantages and disadvantages. For a detailed analysis please read the documentation that comes with the program files.
Please comment if you like the software and give us feedback! We would be glad to head your opinion! Thank you!
2011-07-31 – version 1.0
- inital version
- implemented off-screeen visualizations: wedges, arrows, halos
- basic input and details-on-demand
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Unfortunately, the download is not available anymore on this website! If you still would like to get it, please contact me!
If you are interested in this project and would like more information on our work, please write me a mail or leave a comment!