An icosahedron has 20 similar regular triangular faces.
The following examples show the same Icosahedron using different
projections:
default_focus.set(3, 0, -10, 2, 0, 10, 10);
Icosahedron i(origin, 3);
i.draw();
Fig. 45.
Fig. 46.
Fig. 47.
Fig. 48.
In [next figure]
, i is filldrawn. In this case,
the surface hiding algorithm has worked properly.
See Surface Hiding.
Fig. 49.