3D Scanning and Printing

additive vs subtractive processes

printing
   constraints
      materials
         ABS, HIPS, acrylic, PLA
      resolution
      time
      cost
      supports
      post-processing
      wall and edge thickness
      clearances
      orientation
      fills
   processes
      stereolithography
      fused-deposition molding extrusion contour crafting
      ink-jet binder
      ProJet PolyJet
      cut sheets
      selective laser sintering
      CLIP
      two photon
      digital
   machines
      RepRap
      Ultimaker
      MakerBot
      Sindoh
      Formlabs
      MTM
   service bureaus
      Shapeways
      Ponoko
      Additively

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)
      (lack of) units
   PLY
   AMF 3MF
   OBJ, 3ds, DXF
   VRML, X3D
   FREP, BREP
      adaptively-sampled distance fields
   volumetric
      .vol, .tiff, .gif
      marching cubes
      fab modules vol_gif gif_stl gif_png

software
   123D
   SketchUp
   Fusion 360
   SolidWorks
   Rhino Grasshopper
   Blender
   FreeCAD
   OpenSCAD
   Antimony
   VTK
   MeshLab netfabb meshmixer
   Geomagic
   ReplicatorG Skeinforge Slic3r Cura
   Sketchfab

scanning
   point cloud, triangulation, watertight, texture
   tomography Radon transform micro-CT
   scanned probe
   confocal
   serial sections
   opacity
   digitizer
   laser
   lidar
   array illumination
   time of flight
   photogrammetry 123D Catch PhotoScan VisualSFM
   speckle OpenKinect ReconstructMe Sense
   structured light laser pico-projector
   light stages
   SLAM

assignment
   * test the design rules for your printer(s) (group project)
   * design and 3D print an object (small, few cm) that could not be made subtractively
   * 3D scan an object (and optionally print it) (extra credit: make your own scanner)