网络环境下基于外存的大规模流程工厂模型交互绘制  

Network-Based Interactive Rendering of Large-Scale Process Plant Models

作　　者：苏智勇[1,2] 唐卫清[1,3] 李蔚清[4] 何涛[1,3] 

机构地区：[1]中国科学院计算技术研究所,北京100190 [2]中国科学院研究生院,北京100049 [3]北京中科辅龙计算机技术股份有限公司,北京100085 [4]南京理工大学计算机科学与技术学院,南京210094

出　　处：《计算机辅助设计与图形学学报》2010年第1期66-75,共10页Journal of Computer-Aided Design & Computer Graphics

摘　　要：现有的基于网络的远程绘制系统在绘制过程中对网络带宽和时延具有较强的依赖性,为了获得较高的绘制速度,需要耗费大量的预处理时间和存储空间.针对网络环境下模型的设计校审工作对预处理时间、绘制速度和图像质量的实际需求,提出一种基于外存的大规模流程工厂模型交互绘制算法.绘制前,首先从服务器端获取模型的几何参数和拓扑信息;然后根据流程工厂模型特征,在客户端以设备和管线为基本单位组织外存数据,采用体元合并的方法快速完成模型层次细节的计算和存储.分析了校审内容和校审人员的运动习惯,并将其与基于视点可见性的预取算法相结合,在本地实现外存数据的高效预取,且绘制过程中无需传输模型面片信息.实验结果表明,文中方法在普通PC机上能够将具有21 M左右面片模型的预处理时间控制在5 min以内,在保证校审所需图像质量的前提下取得平均30帧/s的平稳帧速,且绘制过程不依赖网络带宽和时延.The performance of current network-based remote rendering systems relies on the bandwidth and latency of the network during visualization.In order to gain high frame rates,they need time consuming preprocessing and additional storage.Design review has practical requirements on the preprocessing time,frame rates and visual fidelity.In this paper,a network-based interactive out-of-core rendering system for large-scale process plant models was proposed.First,the model＇s geometry parameters and topology information are transmitted from the server before visualization.Then the model＇s out-of-core representation is organized and computed locally according to the model feature.By analyzing the content and motion characteristic of the reviewer,a novel visibility-based pre-fetching technique is presented.It takes into account the reviewer＇s motion characteristic.No triangles are transmitted during visualization.The algorithm can be implemented on a general PC over the network.It can preprocess a 21-million-triangles model within 5 minutes and achieve 30 fps smooth frame rates on average without sacrificing the image quality.Experimental results show that the rendering performance doesn＇t depend on the network＇s bandwidth and latency.

关 键 词：基于外存的绘制 预取 基于网络的绘制 分层层次细节模型 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]