DVE中按需预取的递进纹理数据传输方法

很多虚拟环境中的3D模型具有高质量的表面纹理。因此，在大的分布式虚拟环境的应用系统中需要传输大量的纹理数据。然而，分布式虚拟环境中大规模的纹理数据传输带来的传输延时令影响系统的真实感和实时性。为解决这个问题用拉普拉斯金字塔算法和哈尔变换算法实现了纹理递进传输。实验结果和测试数据表明，这两种算法都有效地减少了初始传输延时。但是拉普拉斯金字塔算法增加了表示一幅纹理贴图所需的数据量，而哈尔变换算法则保持数据量不变。为了进一步减轻网络负载，可以用均匀标量量化和行程编码等算法进一步减少在此DVE系统中的所需传输的数据总量。

Implementation of Progressive Texture Transmission in Distributed Virtual Environments

Most practical virtual environments are constructed of 3D models with top-quality textures. Therefore, large application systems of distributed virtual environment inevitably involve huge transmission of texture data. However, transmitting huge texture data over the network will bring severe delays that would affect the characteristics of reality and real-time of Distributed Virtual Environment. To solve this problem we have implemented the texture progressive transmission with the classic Laplacian pyramid algorithm and the Haar transform algorithm. The experimental results in our prototype DVE system show that these two algorithms both effectively decrease initial load latency. However the former algorithm increases the data amount needed to represent a texture map while the latter keeps the amount unchanged. Furthermore to lighten the burden of the network, we use some data compression methods to reduce the total number of the data to be transmitted in our DVE system.