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arma3:terrain:qgis-real-world-data

Real World Data using QGIS

How to get real world data through QGIS into terrain builder and arma3. See our main Real world data tutorial page for the main tutorial part and QGIS real world data tutorial by Ross.

Goal of this WIP page

Goal of this work in progress page is to learn how to get real world data for:

And process these through QGIS (free open source program) into terrain builder and finally into finished arma3 terrain addon.

Install QGIS Plugins

Use plugins → manage and install plugins…

Select OpenLayer and click install, select OSMDownloader and click install.

QGIS Settings

QGIS settings → options → CRS, allows you to setup default CRS for new projects and layers. Set this to EPSG:32631, WGS 84 / UTM zone 31N

Clip Data to Power of Two

Terrains used in arma3 can only be power of two grid, like 256 x 256, 512 x 512, etc. When you get real world data from various web sources its usually downloaded in “hand drawn box” which is not perfect square (power of two), so you must clip this data into square power of two.

PMCTODO now idea how to select power of two square other than typing in lat/lon coordinate numbers

OpenStreetMap

Once you have terrain loaded in QGIS, you can get streets / roads to show transparent on top of it. This is just an image, not actual road shapefiles, see Road Shapefiles Real World Data how to download roads.

Use web → openlayers plugin → openstreetmap → openstreetmap (heh yes twice).

This opens open street maps layer in your project on top of your terrain heightmap. On layers panel double click openstreetmap layer to bring up its properties. Select transparency tab and move global transparency slider to about 50% then click apply and ok.

Now you can see your terrain heightmap and openstreetmap road data together.

You can click the X button in layer panel on each layer to turn them on/off.

You should download OSM shapefiles from geofabrik.de instead.

Google Maps Satellite

Use web → openlayers plugin → google maps → google satellite

Hydrra: Under Open Layers plugin there will be google maps and bing maps tabs that you can use to get your sat image. On both street map and sat map there will be a button two rows under new file icon called download OSM data. Use it then select the area you want to use. let it download then when you have both your street map and sat image use the vector tool and align them. I do believe you also need to set the SRS layer as well. UTM 31.

Hydrra: to get to the vector tool hit Ctrl + alt + T and your toolbox will pop up. Just type in vector and the tool you will most likely need is the transform tool in case your sat image and street map aren't alligned.

Hydrra: Yeah, The plugin provides both sat image and street map. just make sure to separate the layer groups so it's easier to keep track of.

You should download Satellite Texture with Terra Incognita instead.

Export Highres Satellite using QGIS

A simple guide for exporting high resolution satellite maps using QGIS by pooface

Install openweb layers for QGIS

Set your CRS (Coordinate Reference System) in QGIS of which you already know the coordinates of your map extents.

To make this possible, first find your real world location via the openweb layers plugin in QGIS, and give yourself an approximate field of view. The extents do not need to be exact, but it helps print composer.

In toolbar of QGIS find Project → new print composer (CTRL-P) This will open a new window.

  1. add new map button on left side (white paper icon with a green “+”)
  2. draw a generic rectangle

On left side infobar inside composer find:

  1. Item properties tab
  2. under extents, set your coordinate extents based on the CRS you are using (in QGIS at the bottom right)
  3. under Main properties, change from Cache (default) to Render
  4. Go back to Composition tab and under Resize page to content, click Resize page
  5. You should be looking at a preview of your final satellite export framed nicely.

Now you may export:

In the toolbar of the print composer window, under Composer: export as image

  1. set page widgth and height in pixels.
  2. Depending on how you plan to import into terrain builder, set these accordingly

example:
I want my satellite image to be 0.5 meters / pixel.
My terrain is 8192 meters by 8192 meters.
Therefore, I want my page width and page height to both be 16384 pixels.

  1. Save and then wait for export. If you are exporting images of these large sizes, it MAY take a WHILE!
  2. Check your exported image after print composer finishes processing. Often times (for reasons I'm not sure) it may leave holes in your image, in which case I suggest re-exporting.

If you wish to reimport this to QGIS to guide your shapefile creation, you must include a .wld file of the same name as the image you just created.

QGIS Refactor Fields

OSM place names data sometimes comes with different order for the fields, this will break up PMC OSM Places CSV2HPP tool. You can fix this in QGIS by using “Refactor fields” plugin.

In processing toolbox search for “refactor fields”, open it. Now you can reorder the fields mapping dialog list, so if you need to swap “name” and “type” fields, just click one and use the arrow keys to move up or down.

When reorder is OK then just click run button and it creates refactored layer with the new reordered fields.

arma3/terrain/qgis-real-world-data.txt · Last modified: 2018-07-26 21:10 by snakeman