协同虚拟环境中方向更新消息滤波机制研究

方向更新消息滤波机制是协同虚拟环境(Collaborative Virtual Environments，以下简称CVE)中的一个重要研究课题，Dead-Reckoning(以下简称DR)技术是一种有效的更新消息滤波机制。然而，以前的DR技术主要集中在位置更新消息滤波，现有的方向DR算法一般基于固定阈值，方向固定阈值机制(Fixed Threshold Mechanism for Orientations，以下简称FTMO)的缺点将在本文讨论．提出一个方向可变阈值机制(Variable Threshold Mechanism for Orientation，以下简称VTMO)．VTMO首先计算最近平均角速度，并基于最近平均角速度改变方向阈值，从而在保持一定的方向精确度的情况下，减少需发送的方向更新消息的数量。

Orientation Update Message Filtering Mechanism for 3-D Objects in Collaborative Virtual Environments

Orientation update message filtering for 3-D objects is an important issue in collaborative virtual environments (CVE). Dead-reckoning (DR) is a known effective mechanism for update message filtering. Yet, previous dead-reckoning techniques mainly focused on the update message filtering for positions. The existing orientation dead-reckoning algorithms are based on fixed threshold values. The drawbacks of fixed threshold mechanism for orientations (FTMO) are discussed in this paper. Proposeda variable threshold mechanism for orientations (VTMO) based on average recent angular velocity. The main advantage of the proposed VTMO is the ability of balancing the number of state update messages and shift frequency of direction and speed of rotation.