Example compilation process:

1) Update submodules
git submodule update --init --recursive

2) Generate the Godot headers
cd vrpn_client/godot-cpp/
scons godotbinpath="../godot_fork/bin/godot_binary" p=linux generate_bindings=yes
cd ../

3) Compile plugin
./compile.sh

4) Open project.godot and run the example