GeoSkylines general info

Cities: Skylines game mod for import/export of geodata.

Install game mod (if not on Steam workshop):

• use the provided GeoSkylines.dll
• if you want to compile the code you need also additional code from burningmime: https://github.com/burningmime/curves/tree/master/burningmime.curves
• go to c:\Users<username>\AppData\Local\Colossal Order\Cities_Skylines\Addons\Mods\
• create a folder GeoSkylines
• copy the GeoSkylines.dll file to newly created folder GeoSkylines
• in game, go to Content Manager > Mods > turn on GeoSkylines

See the Word document for full details on data-related preparations etc. !

GeoSkylines methods are called using the threading hooks via hotkeys, combination of ONLY RIGHT Ctrl + R, L, W, Q, T, V, S, Z, P, G, H, J, K. To avoid conflicts with hotkeys of other mods, it is recommended to turn off other mods before using GeoSkylines. After using import or export methods of GeoSkylines then you can turn the mod off. (Though this has been limited now to right Ctrl)

Three stages of creating playable model in Cities: Skylines based on geodata:

1. Prepare geodata for import
2. Create base model using GeoSkylines methods
3. Create playable model (manual post-processing)

Prepare vector geodata for import

I chose to use a simple CSV format with geometry data recorded as WKT. Thus, any geo-dataset can be used. For testing I used OSM predominantly. For the CSV file preparation I used OSMSharp library (other programs such as QGIS or FME would suffice). See the code examples of the data preparation using OSMSharp. For preparing the data in QGIS see the Word document! During the data preparation phase I followed these initial steps:

• Deciding on an area to model. The game area is 17.28 x 17.28 km. This fits cities up to 400,000. Above that you will have to model just parts of the city.
• Choose a mid-point of the modeled area - this will also be the mid-point of your model. See the Word document for more details.
• In import_export.txt file set the CenterLatitude and CenterLongitude. Make sure not to swap latitude and longitude!
• Though it's not necessary, I'd recommend also creating a bounding box of your area. This can be done in QGIS (see Word document) or use one of my helper method WgsBbox() in https://github.com/gonzikcz/GeoSkylines/tree/master/OSMSharp_codes
• download geodata using the defined bouding box. In my case I got the OSM data from OverPass API. But actually now I'd recommend QGIS, it's more user friendly. See Word document for more details!
• Filtering out most of the attributes. In most cases I just need the geometry, type of object (e.g. road type). See examples.
• Resulting CSV files should be named: roads_rwo.csv, waterway_rwo.csv, water_rwo.csv, buildings_rwo.csv, amenity_rwo.csv, trees_rwo.csv, zones_rwo.csv.

Prepare raster image for tree coverage

There is a GeoSkylines method for creating tree coverage from raster image (trees.png saved in c:\Program Files (x86)\Steam\steamapps\common\Cities_Skylines\Files). See the Word document to prepare the raster image in QGIS.

Prepare tree vector layer

Alternatively, tree coverage can be created from vector data as well. To prepare the file trees_rwo.csv, follow the steps described in the Word document.

Import methods of GeoSkylines mod

GeoSkylinesImport.ImportRoads():

• Run by hotkey combo: right Ctrl + R
• Requires: roads_rwo.csv, rwo_cs_road_match.csv, import_export.txt
• Description: loops over all road segments in roads_rwo.csv, matches road types according to rwo_cs_road_match.csv, creates game nodes and then game roads, names the roads according to geodata orginals, creates a bridge if original data says bridge = yes, creates one way roads.
• Note: it’s better to call this method in actual game not the map editor. That way you can see the progress on the screen (segments appearing) and also the roads stick better to the surface. In map editor the roads are bit elevated.

GeoSkylinesImport.ImportRails():

• Run by hotkey combo: right Ctrl + L
• Requires: rails_rwo.csv, rwo_cs_rail_match.csv, import_export.txt
• Description: loops over all rail segments in rails_rwo.csv, matches rail types according to rwo_cs_rail_match.csv, creates game nodes and then game rails.
• Note: C:S doesn’t use that many railways as in the real world. The amount of railways created by this method is therefore too much for C:S. Either filter out the geodata first or buldoze it after creation.

GeoSkylinesImport.ImportWaterBody():

• Run by hotkey combo: right Ctrl + W
• Requires: water_rwo.csv, import_export.txt
• Description: loops over all records of standing water defined by a polygon in water_rwo.csv, creates a bounding box around polygon, then every 5 metres withing the bounding box calls Ray casting algorithm to find out whether point is within polygon or not. If yes, then lower terrain by defined value (variable ImportWaterDepth, see more details below).

GeoSkylinesImport.ImportWaterWay():

• Run by hotkey combo: right Ctrl + Q
• Requires: waterway_rwo.csv, import_export.txt
• Description: loops over all segments of water way in waterway_rwo.csv, lowers terrain by defined value (variable ImportWaterWayDepths, see more details below) every 5 metres between the vertices of each segments.

GeoSkylinesImport.ImportTreesRaster():

• Run by hotkey combo: right Ctrl + T
• Requires: trees.png (1081 x 1081 resolution), import_export.txt
• Description: loops over every pixel and for every non-white pixel it creates a tree. If variable ImportTreesRasterMultiply is defined, method adjust the number of trees created (see more details below). Method adds randomness into the position of the created trees.

GeoSkylinesImport.ImportTreesVector():

• Run by hotkey combo: right Ctrl + V
• Requires: trees_rwo.csv, import_export.txt
• Description: loops over all trees in trees_rwo.csv and creates a tree.

GeoSkylinesImport.ImportZonesArea():

• Run by hotkey combo: right Ctrl + Z
• Requires: buildings_rwo.csv, rwo_cs_zone_match.csv, import_export.txt
• Description: sets zones to existing zone blocks (must be called after creating roads, this will create zone blocks as well). First it loops over every building in buildings_rwo.csv, finds zone blocks near the position of the building, matches the building type to a game zone (e.g. building type = house to zone = ResidentialLow) according to rwo_cs_zone_match.csv and then assigns selected zone to the zone blocks.

GeoSkylinesImport.ImportServices():

• Run by hotkey combo: right Ctrl + S
• Requires: amenity_rwo.csv, rwo_cs_service_match.csv, import_export.txt
• Description: loops over every amenity (service) in amenity_rwo.csv, matches amenity type to a game service building according to rwo_cs_service_match.csv and creates a service building.
• Note: the service buildings created by this method doesn't seem to work properly but still it might be handy to know where the services are. It can be buldozed and then re-created manually.

GeoSkylinesImport.ImportBuildings():

• Requires: buildings_rwo.csv, import_export.txt
• Description: loops over every building in buildings_rwo.csv, tries to calculate the right building rotation angle and creates the building.
• Note: this method is not used due to many complications. Difficult to calculate the right rotation angle, buildings are offten to close to the roads, and mainly: creating buildings directly goes against the game logic where only zones are set. Although this can be overcome by mods, it was still quite unusable.

Export methods of GeoSkylines mod

GeoSkylinesExport.ExportSegments():

• Run by hotkey combo: right Ctrl + G
• Requires: import_export.txt
• Description: loops over all roads created in the game and exports them as GIS data (CSV format, geometry in WKT, any meaningful information about the road as attributes).

GeoSkylinesExport.ExportBuildings():

• Run by hotkey combo: right Ctrl + H
• Requires: import_export.txt
• Description: loops over all buildings created in the game and exports them as GIS data (CSV format, geometry in WKT, any meaningful information about the building as attributes).

GeoSkylinesExport.ExportZones():

• Run by hotkey combo: right Ctrl + J
• Requires: import_export.txt
• Description: loops over all zones created in the game and exports them as GIS data (CSV format, geometry in WKT, any meaningful information about the zone as attributes).

GeoSkylinesExport.ExportTrees():

• Run by hotkey combo: right Ctrl + K
• Requires: import_export.txt
• Description: loops over all trees created in the game and exports them as GIS data (CSV format, geometry in WKT, any meaningful information about the tree as attributes).

Helper methods of GeoSkylines mod

GeoSkylinesExport.DisplayLLOnMouseClick():

• Runb by hotkey combo: right Ctrl + left mouse click
• Requires: import_export.txt
• Description: Displays in a message box screen, game and Lat Lon coordinates of the place of the click.

GeoSkylinesExport.OutputPrefabInfo():

• Run by hotkey combo: right Ctrl + P
• Requires: nothing
• Description: outputs all road types (NetInfo), building types (BuidlingInfo) and tree types (TreeInfo) loaded currently in the game into "c:\Program Files (x86)\Steam\steamapps\common\Cities_Skylines\Cities_Data\output_log.txt".
• Note: this is valuable for creating the match CSV files and setting some variables in import_export.txt

Configuration of import and export methods

CSV files for import, CSV files for matching types of objects, trees.png file and import_export.txt file have to be stored in folder: c:\Program Files (x86)\Steam\steamapps\common\Cities_Skylines\Files. This folder is also used to store CSV files to output game objects as GIS data using the export methods (e.g. roads_cs.csv).

File import_export.txt lists parameters for configurying the import and export methods. Here's the complete list of parameters.

MapName:

• Description: not used in the code, just a label for distinguishing the file from others
• Example: Svit

CenterLatitude:

• Description: Latitude of the defined mid-point. Coordinates of the mid-point are used for conversion between real-world WGS coordinates and the game coordinates. It should be pretty accurate in order to get accurate conversion of coordinates.
• Example: 49.063148018262

CenterLongitude:

• Description: Longitude of the defined mid-point. Coordinates of the mid-point are used for conversion between real-world WGS coordinates and the game coordinates. It should be pretty accurate in order to get accurate conversion of coordinates.
• Example: 20.1857094521613

ImportRoadsCoordMax:

• Description: Specifies the max coord (in both directions - positive and negative) for creating game objects. Game area is 17280 x 17280, thus axes x a z range from -8640 to 8640. This represents 9x9 tile. If no value is defined, then the absolute 8640 will be used.
• Example: 4800 (this represents the area of 5x5 tiles, game objects won't be created past this)

ImportRailsCoordMax:

• Description: Specifies the max coord (in both directions - positive and negative) for creating game objects. Game area is 17280 x 17280, thus axes x a z range from -8640 to 8640. This represents 9x9 tiles. If no value is defined, then the absolute 8640 will be used.
• Example: 4800 (this represents the area of 5x5 tiles, game objects won't be created past this)

ImportBuildingsCoordMax:

• Description: Specifies the max coord (in both directions - positive and negative) for creating game objects. Game area is 17280 x 17280, thus axes x a z range from -8640 to 8640. This represents 9x9 tiles. If no value is defined, then the absolute 8640 will be used.
• Example: 4800 (this represents the area of 5x5 tiles, game objects won't be created past this)

ImportTreesRasterOffTolerance:

• Description: Sometimes the created map image is not exactly 1081 x 1081 but instead few pixels off (but still close enough). In this case you can specify the number of pixels the map image is off. The code will work only with map images that are within range (1081 - ImportTreesRasterOffTolerance) to (1081 + ImportTreesRasterOffTolerance).
• Example: 1

ImportTreesRasterOffsetX & ImportTreesRasterOffsetY:

• Description: If the tree map image (and the game trees generated based on the map image) doesn't align with other layers (roads, water basins) then it's possible to use ImportTreesRasterOffsetX & ImportTreesRasterOffsetY to move it around and align it with other layers.
• Example: 100 (metres)

ImportTreesRasterMultiply:

• Description: To make tree coverage denser or less dense (e.g. to avoid reaching the game limit 250 000 of trees created), you can use parameter ImportTreesRasterMultiply. The number specifies a step at which tree creation will be skipped (if number is negative) or an additional tree will be created (if number is positive).
• Example A: -2 (every second tree creation will be skipped, i.e. the total number of trees will be divided by 2)
• Example B: 1 (at every tree creation, new additional tree will be created, i.e. multiplying the number of tree by 2).

ImportTreesTreeTypes:

• Description: For adding diversity in the tree creation process. List of ID of a TreeInfo (prefab) instances. It has to be IDs as names getting the TreeInfo from name didn't work in the code. For each tree creation, one TreeInfo is randomly selected from the provided list.
• Example: 0,1,2,6,14,13 (you can use the helper method GeoSkylinesExport.OutputPrefabInfo() to list IDs of all TreeInfo instances)

ImportTreesCoordMax:

• Description: Specifies the max coord (in both directions - positive and negative) for creating game objects. Game area is 17280 x 17280, thus axes x a z range from -8640 to 8640. This represents 9x9 tiles. If no value is defined, then the absolute 8640 will be used.
• Example: 8640 (this represents the area of 9x9 tiles, game objects won't be created past this)
• Note: lower the max coord if you need to lower the total number of trees if reaching the tree limit is a problem.

ImportWaterWayTypes:

• Description: List of waterway types that the code will work with. Any other water way type will be ignored.
• Example A: river
• Example B: river, stream, canal

ImportWaterWayDepths:

• Description: List of depths for water way types defined by ImportWaterWayTypes.
• Example: 15, 10, 10 (assuming "ImportWaterWayTypes=river, stream, canal" then river basins will be 15 metres deep, stream and canal basins will be 10 metres deep).
• Note: the depths must be exgaragated for the game water dynamics to work properly

ImportWaterWayWidths:

• Description: List of additional widths for water way types defined by ImportWaterWayTypes. One "width" represents 16x16 metres on 1081 x 1081 grid.
• Example: 1, 0 (assuming "ImportWaterWayTypes=river, stream" then river basins will width=2, stream basins will have width=1)

ImportWaterDepth:

• Description: Defines the depth of standing water basins.
• Example: 15

ExportCoordsBox:

• Description: Xmin, Zmin, Xmax, Zmax game coordinates - only game objects within this bounding box will be exported. If not defined then bounding box is set to max (i.e. all game objects are exported).
• Example: -250, -250, 1000, 1000
• Note: avoid using 0 as 0 will be considered as failed attempt to set the coordinate (and thus set to max coord). Instead of 0 use -1 or 1.

Create a playable model in Cities: Skylines (post-processing)

Calling the GeoSkylines' import methods creates just a geographically accurate base model. However, it has to be manually processed to create a playable model. Sources of water have to be added to the water basins. Connection to a highway has to be created in order for new citizens to move in. The created game objects must be fixed in some cases (e.g. due to bad input GIS data). It is recommended that the post-processing is done by an experienced C: S player.

Acknowledgements

This mod was inspired by another C: S mods, mainly Cimptographer (Mapper). The curved segments in this mod are created with library burningmime.curves. Data from OSM were mainly prepared with library OSMSharp. Big thanks to all these creations and their authors!