Authors: 
Xin Tong, Chun-Ming Chen, Han-Wei Shen, Pak Chung Wong
Abstract: 
Occlusion presents a major challenge in visualizing 3D flow fields using streamlines. Displaying too many streamlines creates a dense visualization filled with occluded structures, but displaying too few streams risks losing important features. A more ideal streamline exploration approach is to visually manipulate the cluttered streamlines by pulling visible layers apart and revealing the hidden structures underneath. This paper presents a customized deformation algorithm and an interactive visualization tool to minimize visual cluttering. The algorithm is able to maintain the overall integrity of the flow field and expose the previously hidden structures. Our system supports both mouse and direct-touch interactions to manipulate the viewing perspectives and visualize the streamlines in depth. By using a lens metaphor of different shapes to select the transition zone of the targeted area interactively, the users can move their focus and examine the flow field freely.