Visualizing 2D Flows with Animated Arrow Plots

Figure 1: Ocean currents visualized with a set of dynamic arrows. (Left) The domain is filled with arrows aligned with the flow. The length is proportional to the velocity magnitude. The arrow density is controlled by a custom map to better capture local turbulences. (Right) Close-up showing the arrow trajectories and the morphing of their glyphs. Flow fields are often represented by a set of static ar-rows to illustrate scientific vulgarization, documentary film, meteorology, etc. This simple schematic represen-tion lets an observer intuitively interpret the main proper-ties of a flow: its orientation and velocity magnitude. We propose to generate dynamic versions of such representa-tions for 2D unsteady flow fields. Our algorithm smoothly animates arrows along the flow while controlling their density in the domain over time. Several strategies have been combined to lower the unavoidable popping artifacts arising when arrows appear and disappear and to achieve visually pleasing animations. Disturbing arrow rotations in low velocity regions are also handled by continuously morphing arrow glyphs to semi-transparent discs. To sub-stantiate our method, we provide results for synthetic and real velocity field datasets