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Visualization, 2009-03-18

Lars Kjelldahl, lassekj ’at’ csc.kth.se

Gustav Taxén, gustavt ’at’ csc.kth.se

(Jonas Forsslund)

Administrative issueshttp://www.csc.kth.se/utbildning/kth/kurser/DD2257/visual09/

Please dofaun> res checkin visual09As soon as possible

And register for the course

Literature: The main text book is expected to be The Visualization Toolkit An ObjectOriented Approach to 3D Graphics, Will Schoeder, Ken Martin and Bill Lorensen, 4thEdition. You can buy the book from the CSC studentexpedition ( afew copies left). It isalso available from Kitware (kitware.com).

A set of papers (see website)

Lab assignments: Two or three of OpenDX, VTK, InfoVis

Exam:• home exam to be sent to lassekj ’at’ csc.kth.se (deadline 27 May)• oral exam to follow up the home exam

Schedule• F1 we 18.3, 15-17, 1537, Intro, Lars Kjelldahl, Gustav Taxén• Fextra, fr 20.3, 13-15, 1537, Overview of C++, Gustav Taxén• F2 we 25.3, 13-15, 1537, Fundamental visualizaion techniques, Kjelldahl• F3 we 25.3, 15-17 1537, Fundamental visualizaion techniques using VTK,

Gustav Taxén• lab session, mo 30.3, 10-12, Magenta, VTK-labb, OpenDX, Gustav

Taxén/Jonas Forsslund• lab session th 2.4 13-15 Violett OpenDX, Gustav Taxén• F4 we 15.4, 15-17, 1537, Interaction in visualization, Yngve Sundblad• lab session xxx 2h, xx, lack of access to computer rooms VTK/OpenDX,

(Gustav Taxén/Jonas Forsslund)• F5-F6 we 22.4, 13-17, 4523, Information visualization, Gustav Taxén,

OlikView lecture• lab session mo 27.4, 13-15 Magenta, VTK, (Gapminder - preliminary)• F7 tue 28.4 13-16 1537 Application lectures• F8 tue 28.4, 16-18, 4523, Visualization of uncertainty, Kai-Mikael Jää-Aro• F9 tue 5.5, 13-15, 1537, Conclusions, exam, Lars Kjelldahl• lab session xxx, 2h, xx, final session for lab assignments

Do you need visualization?Very simple example

What is visualization?

Exploration of data to gain rapidunderstanding of previously unknowncomplex structures and relationsembedded in the data using the highcapacity of the human brain to interpretvisual information

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Scientific visualizationvs. Information visualization

• Information visualization: you want tovisualize information with a ratherundefined structure such as a library ofbooks

• Scientific visualization: you want tovisualize data that you have measuredor got from calculations, often a hughamount of data, but rather well defined

Information visualization

Advection - flow

Particle traces: trajectories traces by fluid particles over timeStreaklines: particle traces at time t(i) that have previouslypassed through a point x(i)Streamlines: integral curves along a curve

Computer graphicsComputer graphics is used invisualization systems to render thepictures that are calculated. Included inc.g. are things such as illumination,hidden surface removal, texturing,…

Examples of visualizationtechniques/methods

• Scalar visualization, Streamlines, streaklines,particle traces

• Surface rendering, glyphs, contouring,…• Volume rendering• Ray casting, splatting, slicing, animation• Stream ribbons, stream surfaces, stream

polygons• Colour mapping, transfer function• Interaction/Multidimensional: Haptics/sound/etc…

Algorithms, examples

• Marching cubes• Dividing cubes• Contour Stitching• Multi resolution techniques• Adapative Mesh Refinement• Interpolation techniques…

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Applications, examples

• Fluid dynamics• Medicine, Virtual Autopsies,…• Chemistry• Air traffic control• Dental surgery simulator• City Planning• Collaboration• Uncertainty

Visualization pipeline

Insight!RenderingArchive

Experiment

Computation

Computer-representation

Transformation/Filtering

Image control

Process steering

Computational steering

Vertex

Cell types

Polyvertex

Line

Polyline

Triangle

Triangle strip

Quadrilateral

Polygon

Software

• MVE (Modular Visualization Environment),such as OpenDX/DataExplorer, AVS

• Software toolkits, such as VTK, libraries ofwith functions usually available from aprogramming language, more flexibility, butmore learning needed

• Specialized visualization applications, suchas Vis5D

OpenDX

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Domain-specific tools can be both effectiveand efficient. This is VMD.

Applications

Alfvén waves, Walter Gekelman, 080910

Sightline

Examples of CSE activities atKCSE:

• Life Science– Simulation of biological structures

• Materials Science– Simulation of iron structure in earth

core• Fluid Systems

– Turbulence simulations• Engineering Design and

Optimization– Simulation of lightning strike

• Computational Neuroscience– Simulation of brain activity

2 .1 3

C 6 : S= 0 .6 3

C 5 : S= -.2 5

S= 0 .4 8

1 .4 3

1 .4 1

1 .4 9

S= - .1 4

Computational Science andEngineering (CSE)

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Sandström, simulation of spread of fire for games Kallin, fluid of water for games

Collaboration Gas flow

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Radiation pattern in a radar antenna VIRTUAL AUTOPSIESLinköping, CMIV

•• From body bag to bones in a minuteFrom body bag to bones in a minute

•• Real-time full body rendering (6 GB volume)Real-time full body rendering (6 GB volume)

Simulator for extraction of teeth

Forsslund

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Saturation

Spectral

Intensity

Spectral and double-endedcolour scales

1. ExplorationThree kinds of use 2. Explanation

3. Education

Use VR to let student put together the parts of a pumpand to let students put together molecules

Evaluation techniques forvisualization

Knowledge and techniques from HCI can beused improving interaction in visualization andalso to evaluate visualization presentationsToday there is an awareness of the need forevaluations, but this awareness has not alwayscome to a mature stage that use existingtechniques in human computer interaction.

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Visualization of information in global networkswas evaluated during the design and implementation

Sami Matilainen

Marching cubes, algorithm fordrawing contour surfaces

Literature and informationsources on visualization

OpenDX—Paths to VisualizationSchroeder, Martin, Lorensen, Visualization

Toolkit, 4rd editionhttp://portal.acm.org/dl.cfmhttp://ieeexplore.ieee.org/Xplore/dynhome.jsp

Initiatives/activities onvisualization at KTH

• VIC, visualization network at KTH• Meeting place VIC Stockholm

Visualization, Interaction, Collaboration• Hardware application, Wallenberg,

together with Norrköping• Heavy projects, KKS, 3 at KTH/SICS