TerraGear

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A wireframe view of detailed CORINE and OSM scenery, generated by TerraGear.

TerraGear is a collection of open-source tools and rendering libraries which can transform publically available GIS data in 3D representations (i.e. 3D models or 3D maps) of the earth for use in real time rendering projects. TerraGear can import 3D data sets such as DEM terrain grids, 2D polygon data sets such as coastlines, city outlines, lake outlines, and 2D raster data sets such as the 1 km NAOO land use/land cover data. It also has tools for generating realistic airports, runways, and lighting based on available FAA data.

TerraGear is the primary tool used to generate the scenery for the FlightGear project.

Introduction

For a variety of reasons you might want to build terrain yourself, rather than downloading it from the available scenery on FlightGear. For instance, if you use WED to create or modify an airport layout, you might wish to see how that modified airport would look in the Scenery before deciding you're happy with the results. And normally, to see and use the airport in the scenery, it's necessary to submit the modifications to the FlighGear scenery staff and then wait untill the next update of the scenery of that area is available via TerraSync or in the official FlightGear Scenery build. If you can build terrain yourself, you can start using it right away.

Maybe the official scenery is too detailed for your slow machine, and you'd like to build terrain using a digital elevation model (DEM) with poorer resolution, to decrease the number of polygons and thus improve your framerates. Or maybe you've got a fantastically fast machine, and you want to build your own terrain using higher resolution vector data (vmap1, Tiger) to get better roads/rivers. For all these reasons learning how to use TerraGear is a good idea.

Getting TerraGear

Using the download_and_compile.sh script

Get the script download_and_compile.sh if you don't already have it. Copy it intp a specific directory, no need to be root.

wget http://sourceforge.net/p/flightgear/fgmeta/ci/next/tree/download_and_compile.sh?format=raw
chmod 755 download_and_compile.sh
./download_and compile.sh SIMGEAR TERRAGEAR

This will build SIMGEAR (pre-requisite) and TERRAGEAR properly, installing dependencies if necessary and you will be done for the TG compilation part of the process.

Pre-compiled builds

Source

The source is hold in a Git repository at SourceForge and a mirror at mapserver.

git clone http://mapserver.flightgear.org/git/terragear

Compilation

Dependencies

  • TerraGear
    • SimGear - Not simgear-cs! (simgear-dev package)
      • SimGear can be compiled without OSG support thus eliminating many deps, like OSG. Use "-DSIMGEAR_HEADLESS=YES" for a minimal build.
    • CGAL - For high accuracy geometric calculations
    • libgdal

Building

cmake . [options]  
make install

cmake options:

-DCMAKE_PREFIX_PATH="/path/to/lib/install/prefix"

Platform specific

GUI Tool

A TerraGear GUI is available for those that would like to use TerraGear without knowing/using the command line options.

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