Painter's Algorithm

Painter's Algorithm

• Idea: Draw polygons as an oil painter might: The farthest one first.
  • Sort polygons on farthest z
  • Resolve ambiguities where z's overlap
  • Scan convert from largest z to smallest z

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• Since closest drawn last, it will be on top (and therefore it will be seen).
• Need all polygons at once in order to sort.

Painter's Algorithm

Z overlap

• Some cases are easy:

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• But other cases are nasty!

  

  (have to split polygons)

• algorithm
• Lots of subtle detail