For the purposes of this tutorial I will be generating a small area around London Heathrow (N51W001 tile) in order to use the new airport layout properly. My coordinates were:
Notice that the download buttons are inoperative, since the associated servers have gone offline!
Folder StructureI created a new folder in my FlightGear folder - EGLL. Under this folder, I created the folder "data sources" (for .zip files) and "data" (for extracted files). All other folders will be automatically generated by TerraGear.
Next, I created a new project in QGIS, "EGLL", and saved it in that folder EGLL as EGLL.qgs.
Finally, I added all folders in TerraGUI - as such:
Elevation DataSo, I downloaded tile M30 from Viewfinder Panorama and put it into "data sources". Then, I extracted the files and copies them to a new folder, ../data/SRTM-3. Next, using a handy plugin for QGIS, "load them all", I load the files as a raster layer. If you do not have "load them all", you can instead use Layer > Add Layer > Add Raster Layer or Ctrl + Shift + R to load the .hgt files. I checked the coordinates to make sure that the area I wanted was included, and indeed it was. If it had not been, I would have needed to download layer M31 instead which was farther over to the east.
Next, I selected the layers that I did not need in the bottom left layers tab, and removem them in the menu opened by right clicking, leaving only N51W001. I could then delete the un-needed layers in the /data/SRTM-3 folder. The result was as follows:
Next, I opened up TerraGUI and with the following options started to parse the elevation data.
This took only a few seconds, and produced a new folder "work", containing SRTM-3\w010n50\w001n51 with many .gz files containing all the elevation data.
Landmass DataMeanwhile, I was downloading landmass polygons from OSM.
Once it finished, before I did anything else, I disabled "render" on the bottom toolbar in QGIS. This is vital unless you have a supercomputer as otherwise it will try to render all 500MB of data totally freezing QGIS!I copied land-polygons-split-4326.zip to data sources, extracted, and again copied the files to a new folder "osm_landmass". Then, I made sure that "render" was disabled, and imported it into QGIS using Ctrl + Shift + V (open vector layer). Alternatively, you can use Layer > Add Layer > Add Vector Layer.
Don't worry if you don't see anything happen - that's because render is disabled. I selected the land_polyons in the layer menu and hit toggle editing, then used the select by area tool to select only what I needed.
I then inverted selection using this tool:
and hit Delete (SUPR or DELETE on most keyboards - alternatively use the red trashcan icon on the toolbar) to delete the data, hitting "Yes". Then, I re-enabled "render" and saw this:
(I set the transparency of the HGT data to 50% by right clicking it in the layer menu and hitting properties and changing transparency.)
Finally, I disabled editing mode by clicking "Toggle Editing" again, making sure to save the data. Note that this overwrites the 530MB shapefile... so that's why I kept the .zip in data sources, so for another later project I can just go back to data sources and re-extract the shapefile!
This completes pre-processing of landmass data.
Processing AirportsNext, I looked up using TerraMaster by hovering over the zone to see which airports were in the zone. I found the following:
I then opened up World Editor, made a new project "heathrow-flightgear", and imported each of these airports using the "Import from Scenery Gateway button". By entering the ICAO in the search bar selecting each airport using Shift-Click, then modifying the search and selecting the next airport using Shift-Click, you can import them all at once.
This is the result:
The next step is to go through each airport and remove things that are not needed - specifically, objects, ground vehicles, ground routes, forests, facades, and exclusion zones.
You should keep at least these ones:
- Markings
- Runways
- Taxiways
- Tower, Beacon and Boundaries
I also reccomend to leave lines and draped polygons which you will need to convert to taxiway markings and taxiways.
I left ATC flows and traffic routes in order to create groundnets later.
The next step is to fix various things.
First, I started to parse polygons. The first airport was EGGW.
You can simply select all draped polygons (no need to select ones that are "safety-yellow.pol" or similar - only ones that are concrete or asphalt are needed), go to the edit menu, "convert to", and convert directly to taxiways!
First, I used the "convert to" tool again to replace linear features.
Notice that not all linear features are supported by genapts! You will need to run genapts and see if it gives an error message. It will clearly tell you what linear marking code it cannot recognize (e.g. it cannot recognize the new red lines), so you can use "replace all" in notepad++ to replace with a similar, working code. For instance, I would replace all codes for red line markings with "20", as such:
This may help:
http://developer.x-plane.com/wp-content ... 1-2019.pdf