docs: static GVRPerspectiveCamera makePerspShadowCamera(GVRPerspectiveCamera centerCam, float coneAngle)
      {
          GVRPerspectiveCamera camera = new GVRPerspectiveCamera(centerCam.getGVRContext());
          float near = centerCam.getNearClippingDistance();
          float far = centerCam.getFarClippingDistance();
  
          camera.setNearClippingDistance(near);
          camera.setFarClippingDistance(far);
          camera.setFovY((float) Math.toDegrees(coneAngle));
          camera.setAspectRatio(1.0f);
          return camera;
      }