public static ILight CreateLight(Transform light2world, ParameterSet paramSet)
{
Spectrum L = paramSet.FindOneSpectrum ("L", new Spectrum (1.0));
Spectrum sc = paramSet.FindOneSpectrum ("scale", new Spectrum (1.0));
Point @from = paramSet.FindOnePoint ("from", new Point (0, 0, 0));
Point to = paramSet.FindOnePoint ("to", new Point (0, 0, 1));
Vector dir = @from - to;
return new Distant (light2world, L * sc, dir);
}