Flow Visualization Using Moving Textures

An intuitive way to visualize a flow is to watch particles or textures move in the flow. The early color table animation of [1] was an example of this technique. More recently, van Wijk [2] has proposed advecting and motion blurring particles by the flow field. The LIC method [3, 4, 5] uses integrals of white noise textures along streamlines, moving the weighting function in the integrals from frame to frame to animate the texture motion. The motion blur of the particles and the directional texture blurring from the LIC integration create anisotropic textures which indicate the flow even in a still frame. However they are computationally intensive, and cannot generate animation in real time. The textured splats of Crawfis [6] use a loop of cycling texture maps with precomputed advecting motion blurred spots, and take advantage of texture mapping hardware. These are composited in back to front order in a local region near each data point, and oriented in the direction of the velocity vector, so that the precomputed advection cycle indicates the flow.