[PD] camera lens angle

[marius schebella]

Hi,
I just found out that by changing the clipping plane with [perspec ...( 
it is possible to change the lens angle of the gem camera.
-1 1 -1 1 1 4 (left, right, bottom, top, front, back)
gives an angle of 90 degrees,  -0.5 0.5 -0.5 0.5 1 4 gives an angle of 
~53 and so on. alpha=asin(x/sqrt(x^2 + 1)).
(I just post that because I think it is not so well documented.)
marius.