:returns: matplotlib.path.Path object for the z=0 projection of 
            this polygon.

def get_path(self):
        """
        :returns: matplotlib.path.Path object for the z=0 projection of 
            this polygon.
        """
        if self.path == None:
            from matplotlib import path
            return path.Path(self.points[:, :2]) # z=0 projection!
        return self.path