AMCS / CS 247 – Scientific Visualization Lecture 22...

AMCS / CS 247 – Scientific VisualizationLecture 22: Vector Field / Flow Visualization, Pt. 5

Markus Hadwiger, KAUST

2

Reading Assignment #13 (until Nov 24)

Read (required):• B. Jobard, G. Erlebacher, M. Y. Hussaini: Lagrangian-Eulerian

Advection of Noise and Dye Textures for Unsteady Flow Visualization, TVCG 8(3), 2002http://dx.doi.org/10.1109/TVCG.2002.1021575

3

Quiz #3: Nov 20

Organization• First 30 min of lecture

• No material (book, notes, ...) allowed

Content of questions• Lectures (both actual lectures and slides)

• Reading assignments (except optional ones)

• Programming assignments (algorithms, methods)

• Solve short practical examples

Stream Line Placement

Basic problem: finding seed points

Desired: evenly-spaced stream linesMarkus Hadwiger, KAUST 6

Scientific Visualization, Tino Weinkauf & Jens Krüger, Saarland University, Winter 2011/12

Flow Visualization: Geometry-Based Methods

● Stream line seeding:● 2D: evenly spaced stream lines● Jobart/Lefer 97:

● greedy placement of new stream lines in the neighborhood of already present stream lines

● 2 steering parameters dsep, dtest with dtest < dsep

● Start integration of an arbitrary stream line in forward and backward direction until it● Leaves the domain● Ends in a critical point● Comes closer than dtest to another drawn stream line

● Next stream line: starts in a point with distance dsep to first stream line● Ends when no further stream lines are possible

Scientific Visualization, Tino Weinkauf & Jens Krüger, Saarland University, Winter 2011/12

Flow Visualization: Geometry-Based Methods

Scientific Visualization, Tino Weinkauf & Jens Krüger, Saarland University, Winter 2011/12

Flow Visualization: Geometry-Based Methods

Scientific Visualization, Tino Weinkauf & Jens Krüger, Saarland University, Winter 2011/12

Flow Visualization: Geometry-Based Methods

● Stream line seeding 3D:● evenly-spaced does not make sense● starting on uniform grid:

[Weinkauf 2003]

Scientific Visualization, Tino Weinkauf & Jens Krüger, Saarland University, Winter 2011/12

Flow Visualization: Geometry-Based Methods

● Stream line seeding 3D:● evenly-spaced does not make sense● starting in regions of high vector field curvature (i.e., close to critical

points):

[Weinkauf 2003]

Line Integral Convolution(LIC)

KAUST King Abdullah University of Science and Technology 12

stream lines

Thank you.

Thanks for material• Thomas Hoellt

• Ronny Peikert

• Helwig Hauser

• Meister Eduard Groeller

• Jens Krüger