anchor.diff:  , LASzip
   , libLAS
   , pdal
  +, pcl
   , qtbase
   , qtsvg
   , qttools
  
positive.code:     "-DPLUGIN_IO_QPDAL=ON" # required for .las/.laz support
      "-DPLUGIN_IO_QPHOTOSCAN=ON"
      "-DPLUGIN_IO_QRDB=OFF" # Riegl rdblib is proprietary; not packaged in nixpkgs
    ];
  
    meta = with lib; {
  
negative.code:     LASzip
      libLAS
      pdal
      pcl
      qtbase
      qtsvg
      qttools
  