虚拟内窥镜实时体绘制技术研究

Accelerating the Volume Rendering in Virtual Endoscopy

针对虚拟内窥镜技术中空体素较多和近景因素对视觉影响较大的特点 ,将一帧场景的绘制分为近景和远景两个部分 近景与远景的绘制分别采用加速的光线投射和改进的快速对象投影方法处理 ,较大地提高了当前帧的绘制速度 ;利用相邻帧的连贯性特点 ,将当前帧远景的绘制结果进行变换 ,得到下一帧远景的部分绘制结果 。

Based on the facts that in virtual endoscopy there are many empty voxels and the human vision is more sensitive to near scene, our accelerating algorithm divides the rendering process into near scene and far scene parts. An accelerated ray-casting method is adapted for rendering the near scene and a fast splatting method is adapted for rendering the far scene. The inherent coherence existed in adjacent frames is used to accelerate the navigation speed. A part of far scene of the next frame may be generated by simply transforming part of far scene of the current frame.