1. Using Flow Textures to Visualize Unsteady Vector Fields
sous titre...

2. Overview
Flow textures allow the visualization of unsteady vector fields as an animation of a dense set of particles
The generated animations are
very smooth (high spatio-temporal correlation)
easily and naturally interpreted
The algorithm may be applied to
2D vector fields
3D flows on surfaces

3. Features of our algorithm
Visualization of the following flow properties at every pixel of the domain
direction
orientation
velocity
associated scalar value (temperature, pressure...)
Interactivity
real-time rendering of the animation allowing interactive exploration of the data
integrates the temporal dimension
Intuitive interpretation of the flow evolution

4. Mathematical Background
« Lagrangian-Eulerian » Hybrid approach
compute the evolution of the flow property at every discrete point of the domain
guarantee an optimally high spatial resolution (fine details)
Very interesting compared to classical « lagrangian » techniques (i.e., pure particle tracing)
particles don't cluster together in regions of convergence and don't spread out in regions of divergence
no time is lost in maintaining a uniform particle coverage of the domain

5. Comparison with Classical Techniques
Arrow placement
Pros
simple to implement
Easy to understand local information (harder in 3D)
Cons
only available on a subset of points in the domain
no continuity from one arrow to the next
unintuitive animations
limited arrow density

6. Comparison with Classical Techniques
Field line placement
Pros
good understanding of the flow structure
Cons
difficult to find good seed points to cover the entire domain
lines tend to concentrate in certain regions
difficult to understand unsteady flows

7. Comparison with Classical Techniques
Flow Textures
Pros
information available at every pixel of the domain
intuitive animations
no seed points
good integration within 3D scenes
Cons
more complex programming

8. Image Gallery

9. Dye Injection

10. Dye Injection + particles

11. Flow Texture

12. Flow Texture

13. Flow Texture on 3D Surface

14. Flow Texture on 3D Surface

15. Flow Texture on 3D Surface

16. Flow Texture on 3D Surface