additive vs subtractive processes

printing
   constraints
      materials
         ABS, HIPS, acrylic, PLA, ...
      resolution
      time
      cost
      overhangs
      post-processing
      wall and edge thickness
   processes
      fused-deposition molding
      cut sheets
      multi-jet modeling
      ink-jet binder
      selective laser sintering
      two photon
      digital
   machines
      PP3DP
      Fab@Home
      RepRap
      MakerBot
      Ultimaker
      MTM

file formats
   STL
      ASCII
         solid object_name
            facet normal n1 n2 n3
               outer loop
                  vertex v11 v12 v13
                  vertex v21 v22 v23
                  vertex v31 v32 v33
               endloop
            endfacet
            ...
         endsolid object_name
      binary
         80 byte ASCII header
         32-bit integer number of facets
         50 byte facet records
            32-bit IEEE floats
            normal
            vertices 1,2,3
            2 byte attribute
      right hand rule
      normal (optional)
   OBJ, 3ds, DXF
   VRML/WRL, X3D
   .cad, .math (FRep, BRep, CSG, SAT, lattice, octree)
      bearing .cad .math
   AMF

software
   Inventor
   123D
   SolidWorks
   Rhino Grasshopper
   Art of Illusion
   Blender
   SketchUp
   FreeCAD
   OpenSCAD
   fab modules
   MeshLab
   Geomagic
   GLC_Player
   VTK

scanning
   point cloud, triangulation, watertight, texture
   tomography Radon transform
   confocal
   serial sections
   opacity
   digitizer
   scanned probe
   triangulation   
   array illumination
   video projector
   structured light
   time of flight
   image optimization

assignment
   * 3D scan an object
      - extra credit: make the scanner
   * design and 3D print an object (small, few cm)
      - extra credit: edit and print an object that you scanned