Test whether the given point <code>(x, y, z)</code> is within the frustum defined by <code>this</code> frustum culler.
@param x
the x-coordinate of the point
@param y
the y-coordinate of the point
@param z
the z-coordinate of the point
@return <code>true</code> if the given point is inside the frustum; <code>false</code> otherwise
Test whether the given point <code>(x, y, z)</code> is within the frustum defined by <code>this</code> frustum culler.
@param x the x-coordinate of the point @param y the y-coordinate of the point @param z the z-coordinate of the point @return <code>true</code> if the given point is inside the frustum; <code>false</code> otherwise