一种高效的光线投射体绘制算法

作为体绘制中的一个经典绘制算法，光线投射算法理论简单同时能产生高质量的图像，被广泛应用于医学图像可视化领域。但在绘制过程中有大量的投射光线和体素的重采样，导致绘制速度较为缓慢。为提高绘制的速度，文中提出一种高效的光线投射体绘制算法，通过引入碰撞检测技术减少投射光线的数目，避免冗余光线的采样计算，同时采用光线跳跃方法在碰撞检测包围盒内跳过对空体素的重采样，加快了光线合成的过程。实验结果表明，改进后的算法不仅能保证所需要的图像质量，还能大幅度地减少采样计算的时间，高效地提高绘制速度。

An Efficient Ray Casting Volume Rendering Algorithm

As a classical rendering algorithm of volume rendering,ray casting algorithm has a simple theory and can produce high quality images at the same time,which is widely used in the field of medical image visualization. But,it produces a large number of projecting rays and voxels resampling in the process of rendering,leading to the slow rendering speed. In order to improve the speed of rendering, present an efficient ray casting volume algorithm,the algorithm introduces the technology of collision detection to reduce the number of projecting rays,avoiding redundant ray sample calculations,while using ray leaping method to skip empty voxel resampling in the collision detection bounding box,speeding up the process of synthesis of ray. The experimental results show that,the improved algorithm not only guarantees the image quality required,but also significantly reduces the sampling calculation time,effectively improving the rendering speed.