Satellite 3D Mapping Visualizer Manual
Installation and running
Download the visualizer package and unpack it anywhere on your system. Open a command window in the directory where you unzipped the package and execute
java -jar visualizer.jar -kml <kml_path> -truth <truth_path> -solution <solution_path>
This assumes that you have Java (at least v1.7) installed and it is available on your path.
The -kml, -truth, -solution parameters should point to files containing the KML file describing the target area, the ground truth file and your solution file. You can use absolute or relative paths. The truth and solution file must be in .txt or .zip format as described in the problem statement. A KML and truth file can be found in the data package you can download from the contest's problem description page. The solution file must be created by you.
Other command line options you can use:
- -w <width> : Width of the tool's screen. Defaults to 1500.
- -fake-solution : if present, the tool doesn't load a solution but generates a synthetic one from the ground truth. You may use this to familiarize yourself with the tool before you created your own solution.
- -fake-truth : if present, the tool doesn't load a ground truth file but uses a constant 0 elevation scene that covers the given KML target area as truth. Use this feature to check how your solution looks on areas for which you don't have the ground truth.
- -registration-method <method_name> : one of "rmse" and "medianz". Defaults to "medianz". Note that the "rmse" method is faster.
- -registration-delta <D> : used to speed up registration (by a factor of D^2) by checking only every Dth grid point in both directions. Defaults to 5.
- -fast-registration : if present, registration will be done in a way that's different from the one used in scoring. This is much faster but still approximates the official method reasonably well.
- -full-registration : if present, it overwrites all other registration related settings with the exception of -register-to, and will execute the full, official registration process that uses the "medianz" method with a delta of 1. Unfortunately this may take 5-15 minutes.
- -register-to <x,y,z> : if present, it overwrites all other registration related settings and forcefully registers your solution to the given {x,y,z} offset. The offset should be specified by 3 real numbers separated by commas, without spaces.
- -z-graph-span <max> : if present, the z error distribution in the [-max..max] range is graphed after scoring. By default this graph is not shown.
For a quick start use this command to try the visualizer with a synthetised solution and fast registration:
java -jar visualizer.jar -kml Challenge1.kml -truth Challenge1_Lidar.xyz -fake-solution -fast-registration -registration-method rmse
Operations
Usage of the tool should be straightforward, the 4 panels show 4 different views of the data sets. You can use the drop downs on the right to select what to show in each of them. By default
- top left shows the truth z height map,
- top right shows your solution's z height map. The height maps are grayscale, purple means no data.
- bottom left is the difference map. Black means zero diff or no data. Yellow means your solution is too high, blue means it's too low. Shades from black to yellow, and from black to blue are proportional to the diff's magnitude, capped at a level that you can select in the 'Z diff scale' drop down. So e.g. if the scale is set to 4m then a diff between 0m and 4m are shown with different shades of yellow, and everything higher than 4m is shown in pure yellow.
- bottom right shows a 'relief' view of your solution, i.e. it simulates a scene that is lighted from a given direction.
You can zoom in/out within the views by the mouse wheel and pan the views by dragging.
On startup registration and scoring happens automatically, so the visualizer also serves as an offline tester. The registration algorithm can be parametrized by the -registration-... parameters. Use -full-registration when you want to check what will happen on the scorer server, otherwise it's recommended to use faster options.
Comments, feature requests are welcome, please use the contest forum for this purpose.
Have fun!