Virtual Planet Builder

VirtualPlanetBuilder (VPB) is an OSG tool that generates native OSG data to represent terrain, usually by draping a GEO-TIFF over an elevation model.

Building VirtualPlanetBuilder

The VPB project and code can be found here: https://github.com/openscenegraph/VirtualPlanetBuilder

If you've got an existing FlightGear build, there are some additional dependencies:

• OSG
  • Including NVTT. ('sudo apt-get install libnvtt-dev' - oddly VPB builds without it but then checks for the shared library at runtime...)
• GDAL (https://gdal.org/), Note that this needs to 2.4.X
  • ... which requires PROJ 6 or above (https://proj.org/)
    • ... which requires the sqlite3.11 or above development package (on linux - 'sudo apt-get install libsqlite3-dev')

Note that GDAL and PROJ do not use cmake, so it builds in the source directory as follows:

./configure -prefix=/path/to/install
make

VPB is built using cmake e.g.

cmake -DOSG_DIR=/path/to/OSG/install /path/to/VPB/src
make

Getting Landcover Data

For CORINE data covering Europe, try here: https://land.copernicus.eu/pan-european/corine-land-cover/clc2018

Choose RASTER data, which will download a geo-referenced TIF image.

Getting DEM data.

For SRTM, try here: http://srtm.csi.cgiar.org/

Again, Raster data is fine.

Running VPB

Here are the options I've used to generate some scenery of the UK:

./bin/osgdem --TERRAIN \
--compressor-nvtt \
--compression-quality-highest \
--geocentric \
-t /home/stuart/FlightGear/VPB/data/CORINE/u2018_clc2018_v2020_20u1_raster100m/DATA/U2018_CLC2018_V2020_20u1.tif \
-d /home/stuart/FlightGear/VPB/data/SRTM90/srtm_34_02.tif \
-d /home/stuart/FlightGear/VPB/data/SRTM90/srtm_35_01.tif \
-d /home/stuart/FlightGear/VPB/data/SRTM90/srtm_35_02.tif \
-d /home/stuart/FlightGear/VPB/data/SRTM90/srtm_36_01.tif \
-d /home/stuart/FlightGear/VPB/data/SRTM90/srtm_36_02.tif \
-b -10 50 0 60 \
--PagedLOD \
-l 8 \
-o uk.osgb

• --TERRAIN to use osgTerrain::Terrain database
• --compressor-nvtt --compression-quality-highest to generate native mipmaps
• --geocentric because that's what FG uses
• -t the texture to drape (in this case CORINE)
• -d the DEM to use (in this case pieces of SRTM90)
• -b is the extents in decimal degrees: LON1 LAT1 LON2 LAT2
• --PagedLOD to generate PagedLOD nodes
• -l 5 the number of LOD levels to generate
• -o is the output file, in this case native OSG binary format.