docs: static GVROrthogonalCamera makeOrthoShadowCamera(GVRPerspectiveCamera centerCam)
      {
          GVROrthogonalCamera shadowCam = new GVROrthogonalCamera(centerCam.getGVRContext());
          float near = centerCam.getNearClippingDistance();
          float far = centerCam.getFarClippingDistance();
          float fovy = (float) Math.toRadians(centerCam.getFovY());
          float h = (float) (Math.atan(fovy / 2.0f) * far) / 2.0f;
  
          shadowCam.setLeftClippingDistance(-h);
          shadowCam.setRightClippingDistance(h);
          shadowCam.setTopClippingDistance(h);
          shadowCam.setBottomClippingDistance(-h);
          shadowCam.setNearClippingDistance(near);
          shadowCam.setFarClippingDistance(far);
          return shadowCam;
      }