Digital Michelangelo Project range processing pipeline
				• steps 1.  manual initial alignment      - should have tracked gantry 2.  ICP to one existing scan      [Besl92] 3.  automatic ICP of all overlapping pairs      [Rusinkiewicz01] 4.  global relaxation to spread out error      [Pulli99] 5.  merging using volumetric method      [Curless96]