code: public static double[] shadowOffset(double azimuth, double altitude, double height) {
          double spread = 1 / Math.tan(altitude);
          return new double[]{-height * spread * Math.sin(azimuth), -height * spread * Math.cos(azimuth)};
      }
docs: Return the shadow offset in X and Y directions
  
  @param azimuth in radians from north.
  @param altitude in radians from east.
  @param height of the geometry
  @return