基于体平滑的体绘制纹理伪边界消除算法

直接体绘制能够清楚的显示三维数据场的内部信息,是科学可视化中非常重要的一类方法。其中,基于二维纹理映射的三维数据直接体绘制方法具有绘制速度快、可交互性强的优点。其基本思路是将三维数据体在时间或深度方向形成一组水平纹理切片,通过这些切片的纹理贴图,实现三维数据体的体绘制,在交互性和资源消耗之间取得了较好的平衡。本文针对基于二维纹理映射的直接体绘制方法中在透明与不透明边界产生阶梯状条纹的伪边界问题,提出了一种基于体平滑的算法。该算法通过在透明数据与不透明数据的边界进行体平滑,使采样过程中缺失的数据表现到抽样的切片上,从而在最终图像生成阶段淡化甚至消除阶梯状条纹伪边界。实验结果表明,相对于传统二维纹理映射方法,本算法实现体绘制效果平滑,提高了绘制效果。

Algorithm of Eliminating Illegal Border of Texture Based on the Volume Smooth

Direct volume rendering technology which is a kind of very important method in Scientific Visualization can clearly display the internal information of three dimensional data fields. The method of 3 D data direct volume rendering based on 2D texture mapping has huge advantage in rendering speed and interactivity. The basic method is to turn 3D data volume into a group of horizontal slices in the direction of time or depth and realize 3D data volume rendering through Texture Mapping of these slices, achieving good balance be tween the interaction and resource consumption. In this paper, in order to solve the illegal border problem that a kind of stripe like lad der will appear in the process of blending 2D texture slices, we propose an algorithm based on the volume smooth. In this algorithm, by smoothing the border between transparent data and not transparent data , we can make the data which missed in sampling process dis played on current slices, and fade or even eliminate the illegal border in the final picture formation stage. Application experiment results show that the picture displayed by this method is more smooth and more tally with the actual situation than the picture made by the orig inal 2D texture mapping method.