I got a couple of compilation errors when I tried to build this (against libqt4-dev): In file included from src/render-opencsg.cc:2: src/polyset.h:8:17: error: qgl.h: No such file or directory In file included from src/render-opencsg.cc:2: src/polyset.h:29: error: field 'polygons' has incomplete type src/polyset.h:30: error: field 'borders' has incomplete type make.real: *** [objects/render-opencsg.o] Error 1