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This study explores techniques to improve the visualization of flow using vector components, direction, magnitude, color, and particle systems. It also discusses contour finding mechanisms, asymmetry along paths, and the use of symbols for speed and direction indicators.
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Representing Flow Colin Ware UNH
Vector components Direction Magnitude 2D vector fields Orientation Vector sign bit
2D Flow visualization • A landmark study • Orient • Direction • Magnitude - Image courtesy of Dr.Laidlaw et al.
Perceptual issues • Luminance contrast for detail • Red on green is hard to see (illustrate) • Natural semantics for signalling “more” • Longer • Wider • More dense • More contrasty • More vivid The background is critical
Particle systems for flow vis. • Particles are born (randomly in space) • Have a behavior (moving with the flow) • They leave a trail (a pathline) • Color can change (with speed or age) • Width can change (speed or age) • Particles die
Theory of contour finding Contour finding mechanisms A single column in V1 Field Hayes Hess
The next stage – rapid propagation Prediction Weakest Contour Signal Strongest Contour Signal
2D Flow visualization • A landmark study • Orient • Direction • Magnitude - Image courtesy of Dr.Laidlaw et al.
Halle, 1868 How to add VSB? Asymmetry along path Terminations Some neurons respond only with terminations in the receptive field. Halle’s “little stroaks” Fowler and Ware (1988)
Continuity tangential to flow sream Lightness contrast with background (clarity) Show direction using asymmetry along path Use color width | length | contrast | density for speed, or a combination Add symbols if you like Trace forward and/or backward. Important factors