I. Introduction
With the continuous development of 3D laser scanning technology, the acquisition accuracy of the point cloud data is significantly improved while the acquisition speed is getting increasingly faster [1]. Since point cloud data can be used as accurate representations of real-world scenes and provide end users with a rich and realistic immersive visual experience, it is soon widely applied in many fields including autonomous driving, heritage reconstruction, virtual reality (VR) and augmented reality (AR) [2].