Painter's Algorithm

Given
    List of Polygons { P1, P1, ... , P1 }
    An array Intensity [x, y]

Begin
    Sort polygon list on minimum Z 
         (largest Z-value comes first in sorted list)

    for each polygon P in selected list do
       for each pixel (x, y) that intersects P do
          Intensity [x, y] = intensity of P at (x, y)

    Display Intensity array