ray/lib/globe.cal

{
        Coordinate mapping for globe onto unit sphere
        assuming uniform projection of latitude and longitude

        A1 = image height/width
}

globe_u = if(A1-1, 1, 1/A1) * (.5 + Atan2(Py, Px)/(2*PI)) ;

globe_v = if(A1-1, A1, 1) * (1 - Acos(Pz)/PI) ;
Revision:	1.1
Committed:	Wed Mar 12 17:45:48 2003 UTC (22 years, 1 month ago) by greg
Branch:	MAIN
Log Message:	Added the rest of the missing files to ray/lib/
#	User	Rev	Content
1	greg	1.1	{
2			Coordinate mapping for globe onto unit sphere
3			assuming uniform projection of latitude and longitude
4
5			A1 = image height/width
6			}
7
8			globe_u = if(A1-1, 1, 1/A1) * (.5 + Atan2(Py, Px)/(2*PI)) ;
9
10			globe_v = if(A1-1, A1, 1) * (1 - Acos(Pz)/PI) ;