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Creating-shape-files-in-QGIS-for-map-data.md Normal file

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# Not finished, to be continued
This guide will enable you to create data that the developers can use to enable support for a new map. We will use QGIS, an open-source GIS program to generate this data from various open sources. You need to have QGIS installed, preferably a 3.x+ version with GRASS processing toolbox.
https://www.qgis.org/en/site/forusers/download.html
Here are the basic steps you need to take
## 1) Map projection
Find the correct projection for the map. We already have the center meridian meaning we can figure out the proper UTM projection (https://github.com/pydcs/dcs/blob/master/tools/export_map_projection.py).
`CENTRAL_MERIDIANS = {
"caucasus": 33,
"falklands": -57,
"nevada": -117,
"normandy": -3,
"persiangulf": 57,
"thechannel": 3,
"syria": 39,
"marianaislands": 147,
}`
We can use this [map](https://www.arcgis.com/apps/View/index.html?appid=7fa64a25efd0420896c3336dc2238475) to check out different UTM zones. Then it is a matter of making a new project in QGIS and setting the project CRS to be this.
![Projection](https://user-images.githubusercontent.com/20801481/189474094-89e78347-23b5-440a-b4b5-44862b472276.JPG)
You can add XYZ tiles from this python script to add in a bunch of online satmap tile layers you can use: https://raw.githubusercontent.com/klakar/QGIS_resources/master/collections/Geosupportsystem/python/qgis_basemaps.py
## 2) Outlining the game area
In the correct projection you can now create a new vector polygon layer and add the game area as an overlay. Preferably by gettting actual coordinates from the ME as opposed to freehand editing like i did. Layer-> Create Later -> New shapefile layer
![ShapefileGameArea](https://user-images.githubusercontent.com/20801481/189474224-4870e056-9054-4f6a-96c7-936bb1ce48a8.JPG)
Make sure you use the project CRS (projection) and that it is a polygon. Also make sure you save it to a location so you can retrieve it the next time you open the project.
![GameArea_makepoly](https://user-images.githubusercontent.com/20801481/189474417-cd685745-bce4-4626-b2ac-e0ba62176c4f.JPG)
3) For the ocean I downloaded the OSM Ocean Polygon files (source https://osmdata.openstreetmap.de/data/water-polygons.html). These are WGS84 chunck of ocean. Select all the vector objects that are relevant to the map, and use the Vector->Geoprocessing->Dissolve command to merge the cells into one object. This will output a new temporary layer (can be slow to do). This layer we can now save and reproject it to the relevant UTM projection, like UTM 21S for the Falklands map.