Roland Mas wrote:

>   Hello,
>
>   Does any of you know how I could calculate the *exact* coordinates
> of the tetrahedron points' coordinates?

<1   1   1>
<1 -1 -1>
<-1 1 -1>
<-1 -1 1>

Swiped from Jim Blinn (A Trip Down the Graphics Pipeline, p. 40).  It seems
that the a tetrahedron fits comfortably inside a cube such that two opposite
edges of the tetrahedron are diagonals of opposite faces of a cube (a unit
cube is convenient), and the vertices of the tetrahedron are the vertices of
the cube at those diagonals.

Rotate, translate, and/or scale to suit your needs, but be prepared to lose
precision in some cases.  Still, the above is exact, if you're willing to
accept that orientation.

-Mark Gordon

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