question: public static Vector3 azElToPoint ( double az , double el , Vector3 result ) { if ( result == null ) { result = new Vector3 ( ) ; } Matrix3 mat = Matrix3 . fetchTempInstance ( ) ; mat . fromAngleAxis ( az , Vector3 . NEG_UNIT_Z ) ; Matrix3 mat2 = Matrix3 . fetchTempInstance ( ) ; mat2 . fromAngleAxis ( el , Vector3 . UNIT_X ) ; mat . multiplyLocal ( mat2 ) ; result . set ( Vector3 . UNIT_Y ) ; mat . applyPost ( result , result ) ; Matrix3 . releaseTempInstance ( mat ) ; Matrix3 . releaseTempInstance ( mat2 ) ; return ( result ) ; }
target:  Given azimuth and elevation, return a point in 3D space.