成像速度是影响体绘制应用的关键.为了提高成像速度，提出一种基于 Intel奔腾 SIMD和分割技术的快速体绘制算法.仅仅应用奔腾 SIMD并行技术，常规光线投射算法的成像速度能够提高 2～ 5倍.奔腾 SIMD并行指令与分割技术相结合，减少了大量空采样，进一步提高了成像速度，而且这种简单的分割技术能够快速地适应转换函数的改变.在一台 P4 / 1.6 G的 PC机上，以 5 12× 5 12分辨率渲染时，该算法渲染速度比常规光线投射算法提高了 10多倍，使得等值面的体绘制速度能够达到 1～ 3帧 /秒.实验结果表明，该算法具有渲染速度快、成像质量高等显著优点，而且不需要费时的预处理和特殊体视硬件，具有较大的实际应用价值.

Rendering speed is a key technology of volume rendering. In order to accelerate rendering process, we present a novel imaging acceleration approach based on Intel SIMD and segmentation technologies, which obtain significant speedup without degrading image quality. Only applying Intel SIMD techniques, we can obtain the rendering speed 2～5 times faster than brute force ray casting. SIMD techniques are combined with threshold segmentation to skip large empty samplings, and the rendering speed is further more improved. Because the time of threshold segmenting a large data set is very short, the algorithm can quickly display the rendered image once the threshold values are changed. Experiments have been done on a single processor P4/1.6G PC, and it is 10 more times faster than brute force ray casting and about 1 to 3 frames per second is obtained with the image size 512×512. Our algorithm has some advantages that rendering speed can be greatly accelerated without any specialized purpose hardware and time-consuming preprocessing, and images quality is very high.