一种可交互的体绘制光学传递函数模型

Interactive Optical Transfer-Function Model for Volume Rendering

针对三维数据场可视化过程中兴趣区的交互分离问题,给出了基于体绘制光学传递函数的半自动调节方法。该方法从传递函数的光学模型出发,根据三维数据的光强分布,结合体数据的三维梯度场,给出了体数据的颜色及透明度值分离交互调节的模型。为了提高本方法的实用性,本文采用了交互模型与现代显卡纹理特性相结合的方法来提高交互速度。实验证明,通过实时调节改进传递函数的相关参量,该模型能以大于每秒30帧的交互速度获得兴趣区的最佳视觉分离效果。本方法能在交互体视化的同时实现最佳参量的获取。

To deal with the interactive separation of region of interests （ROI） in the process of three-dimensional （3D） visualization, a half-automatic adjusting method based on the optical model for volume rendering is introduced. According to the optical transfer-function model and the intensity distribution of 3D data, the interactive model is described by adjusting the RGB color and transparency values respectively with the help of the 3D gradient field. In order to make the method more effective, the interactive model and the texture feature of modern graphics are both applied to accelerate the process. The experimental results show that an optimal separating effect is achieved by adjusting the corresponding parameters in the transfer function model in real time. And the frame rate is up to 30 f/s in the interactive process. With this method, the optimal parameters are obtained in the interactive volume visualization.