基于Web的时变体数据的体绘制方法

Volume Rendering of Time-Varing Volume Data in Web

摘要:

传统Web体绘制方法主要集中在利用服务器端进行预处理和绘制任务，浏览器端仅用于呈现绘制结果，这样会造成服务器负载过高，同时，当绘制参数发生更改时，必须向服务器请求新的绘制结果，这样也易受网络延迟的影响。为了解决以上问题，实现在浏览器本地进行体绘制和交互，本文提出一种基于WebGL的体绘制方法，以时变体数据为例，在浏览器端实现光线投射体绘制算法。同时，为了提升绘制效率和减少内存占用，本文基于维度压缩方法，优化时变体数据的预处理过程。最后，本文设计了Web体绘制系统，引入暴风时变数据集以验证方法的有效性，结果表明，本文方法能够在浏览器本地对时变体数据进行体绘制，绘制时间在50ms以下，帧速率可达到50 FPS以上，同时支持实时交互，并且当绘制参数发生更改时，系统能够直接在浏览器端进行重新绘制。

Abstract:

Traditional web volume rendering methods mainly focus on use of server for preprocessing and rendering, the browers is only used to be display the rendering result. This will cause high server load. Moreover, request for new rendering result must be sent to server when rendering parameters change, which is also susceptible to network latency. To solve the above problems, realizing volume rendering and interaction in browsers, a WebGL-based volume rendering method is proposed in this paper, which implemented ray-casting algorithm, taking time-varing volume data as example, in browers. In addition, for reducing rendering time and memory usage, the preprocessing of volume data is optimized based on dimension compression method. Finally, this paper designed a web volume rendering system, and introduced Isabel Hurricane data sets to verify the effectiveness of the methods. The results show that this method can realize volume rendering of time-varing data in the browser. The rendering time is less than 50ms, and the frame rate can reach more than 50FPS. Furthermore, it supports real-time interaction and redraw directly in the browser when the rendering parameters change.