CMakeLists.txt
Add_Subdirectory(tree) # special CMakeLists.txt
Add_Subdirectory(treeplayer) # special CMakeLists.txt
Add_Subdirectory(treeviewer) # special CMakeLists.txt
Add_Subdirectory(tree) # special CMakeLists.txt
Add_Subdirectory(treeplayer) # special CMakeLists.txt
Add_Subdirectory(treeviewer) # special CMakeLists.txt