A Technique for Specifying Region of Interest in the Vector Field Based on 3D LIC

Line integral convolution (LIC) is an effective and powerful technique for generating images from vector fields. In the 3D-LIC, it is very important to select an adequate region of interest (ROI) in the vector field. One way for specifying ROI is to use a surface defined in the vector field. Another way is to use a significance map that defines an ROI related value at each point in the vector field. To represent an anisotropic vector field around a vortex center in an understandable way, we introduced a time-oriented significance map. Our technique for specifying ROI is to use a passage-time for a mass-less particle to travel from nearby vortex center to a pixel location. In our technique, what we call “restricted LIC technique (RLIC),” refers to the passage-time buffer before we start the convolution process at a pixel location. The original RLIC technique is 2-D based. In this paper, we extend this technique to 3-D. To confirm the effectiveness of our technique, we use an anisotropic swirl vector field and construct two types of significance maps, a dlstance-oriented map and a time-oriented map. We will show the difference in the resulting images that are generated from these significance maps.