6.1.5 point( name [, optargs] )
A point source. name is a string used for identification
purposes. optargs is a lua
table containing optional
parameters. The following optional arguments are recognized:
theta
-
The distance from the optical axis to the point, in radians. If not
specified, it defaults to `0'.
phi
-
The azimuth about the optical axis, in radians.
If not specified, it defaults to `0'.
z
-
The Z coordinate of the source. It defaults to an infinitely
distant source.