Diapositivo 1 - Sweet - Universidade de Aveiro

What is VTK? 

An Introduction to the 

Visualization Toolkit 

Information Visualization – Paulo Dias 

• Open Source library based in Object 

Oriented Programming 

• multi-platform (Windows/Unix/Mac) 

• C++ implementation with several wrappers 

for other languages (Tcl/Tk-Python-Java) 

• No User Interface but possible to integrate 

with several libraries: Tk, Motif, Visual 

Studio, Qt, … 

Instituto de 

Engenharia Electrónica e 

Telemática 

de Aveiro 

z 

Departamento de 

Electrónica, Telecomunicações e Informática 

Universidade de Aveiro 

deti departamento de electrónica telecomunicações e informática 

universidade de aveiro 

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VTK Goals 

• Scientific Visualization 

• Information Visualization 

• Large Data Visualization 

• Volume rendering 

• 3D Interaction 

What we get 

• Several data representation: points, 

polygonal meshes, images, volumes, 

structured and unstructured grids. 

• Importers and exporters for several 

formats allowing data exchange between 

applications. 

• Hundreds of filters for data processing. 

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The origin 

• VTK Started December 1993 

as supporting software for the 

book “ The visualization Toolkit: 

An Object Oriented Approach 

to 3D Graphics” by Will 

Schroeder, Ken Martin and Bill 

Lorensen (Prentice Hall). 

• Supported by Kitware 

company: 

http://public.kitware.com/VTK/ 

• Software, Books, FAQ’s, 

examples, forums… 

Main characteristics 

• High level of abstraction when compared 

with other libraries such as OpenGL. 

• Support all the main visualization 

algorithms. 

• Hundred of classes and functions. 

• Key to success: 

– Get used to the objects. 

– Use examples. 

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Architecture 

• C++ core: include data structures, 

algoritms and code. 

• Interpretation layers: to allow use with 

several languages : 

– C++ 

– Tcl 

– JAVA 

– Python 

VTK subsystems 

• Graphics 

• Image Processing (2D and 3D ImageData 

and Filter) 

• 3D Geometry (DataSets and Filters) 

• Picking, Interactions 

• 2D Chart API 

• Information Visualization 

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VTK Visualization Pipeline 

VTK Graphic 

data mappers actors 

• Just like hollywood: Lights, Cameras, 

Actors, Properties. The graphics model 

includes tools for 

– Window managing (Creation and 

manipulation of rendering windows). 

– Mappers and their properties. 

– 2D, 3D and volume rendering. 

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VTK Graphic 

Dataset 

A VTK scene consists of: 

• vtkRenderWindow - contains the final image 

• vtkRenderer - draws into the render window 

• vtkActor - combines properties / geometry 

– vtkProp, vtkProp3D 

– vtkProperty 

• vtkLights - illuminates actors 

• vtkCamera - renders the scene 

• vtkMapper - represents geometry 

– vtkPolyDataMapper, vtkDataSetMapper are subclasses 

• vtkTransform - positions actors 

• Dataset structure consists of 

– points (x-y-z coordinates) 

– cells (e.g., polygons, lines, voxels) which are 

defined by connectivity list referring to points 

ids 

• Access is via integer ID 

Points 

Cell 

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Data Representation - Cells and points 

Data Types 

• 5 different type of data: 

• Vertex 

• Polyvertex 

• Line 

• Polyline 

• Triangle 

• Triangle Strip 

• Quadrilateral 

• Polygon 

• Tetrahedron 

• Hexahedron 

• Voxel 

– vtkImageData - Structured Points 

– vtkRectilinear Grid - Rectilinear Grid 

– vtkStructuredGrid - Structured Grid 

– vtkUnstructuredGrid - Unstructured Grid 

– vtkPolyData - Polygonal Data 

• Format choice is important for efficiency and for use 

of adequate filters 

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DataSet Attributes 

• vtkDataSet also has point and cell 

attribute data: 

– Scalars 

– Vectors - 3-vector 

– Tensors - 3x3 symmetric matrix 

– Normals - unit vector 

– Texture Coordinates 1-3D 

– Array of arrays (i.e. FieldData) 

VTK –Example 

#include "vtkConeSource.h" 

#include "vtkPolyDataMapper.h" 

#include "vtkActor.h" 

#include "vtkRenderWindow.h" 

#include "vtkRenderWindowInteractor.h" 

#include "vtkRenderer.h" 

#include "vtkProperty.h" 

void main () 

{ 

// create cone geometry 

vtkConeSource *cone = 

vtkConeSource::New(); 

// create cone mapper for mapping the cone 

to the graphics library. 

vtkPolyDataMapper *coneMapper = 

vtkPolyDataMapper::New(); 

coneMapper ->SetInput(cone->GetOutput()); 

// actor coordinates geometry, properties, 

transformation 

vtkActor *aCone = vtkActor::New(); 

aCone->SetMapper(coneMapper); 

aCone->GetProperty()->SetColor(0,0,1); // 

cone color blue 

// an interactor 

vtkRenderWindowInteractor *iren = 

vtkRenderWindowInteractor::New(); 

iren->SetRenderWindow(renWin); 

// add the actor to the scene 

ren1->AddActor(aCone); 

ren1->SetBackground(1,1,1); // 

Background color white 

// render an image 

renWin->Render(); 

// begin mouse interaction 

iren->Start(); 

cone->Delete(); 

coneMapper->Delete(); 

aCone->Delete(); 

ren1->Delete(); 

renWin->Delete(); 

iren->Delete(); 

} 

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// a renderer and render window 

vtkRenderer *ren1 = vtkRenderer::New(); 

vtkRenderWindow *renWin = 

vtkRenderWindow::New(); 

renWin->AddRenderer(ren1); 

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vtkRenderWindowInteractor 

• SetRenderWindow – render window 

• Key and mouse bindings (Interactor Style) 

• Light Follow Camera (a headlight) 

• Picking interaction 

Interactor Styles 

• Button 1 – rotate 

• Button 2 – translate ( Button 1 for 2-button 

• mouse) 

• Button 3 – zoom 

• Keypress e or q – exit 

• Keypress f – “fly-to” point under mouse 

• Keypress s/w – surface/wireframe 

• Keypress p – pick 

• Keypress r – reset camera 

• Keypress 3 – toggle stereo 

Switch styles: Keypress j – joystick; t - trackball 

style 

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Picking 

• vtkPropPicker - hardware-assisted picking of 

vtkProps (returns vtkProp picked and x,y,z 

coordinate) 

• vtkWorldPointPicker - get x-y-z coordinate; does not 

pick prop (hardware assisted, returns x,y,z 

coordinate) 

• vtkPicker - pick based on prop3D’s bounding box 

(software ray cast – returns vtkProp) 

• vtkPointPicker - pick points (closest point to camera 

within tolerance - software ray cast – returns point id 

& x,y,z coordinate) 

• vtkCellPicker - pick cells (software ray cast – 

returns cell id & x,y,z) 

3D Widgets 

• Added since VTK 4.0 release 

• Requires version 4.2 or later 

• Subclass of vtkInteractorObserver 

• Interactor observers watch events 

invoked on vtkRenderWindowInteractor 

• Events are caught and acted upon 

• Events can be prioritized and ordered 

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3D Widgets 

• vtkPointWidget 

• vtkLineWidget 

• vtkPlaneWidget 

• vtkImplicitPlaneWidget 

• vtkImagePlaneWidget 

• vtkBoxWidget 

• vtkSphereWidget 

• ….. 

Algorithms / Filters 

• Algorithms operate on data objects 

source 

data 

filter 

data 

mapper 

s 

actors 

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Algorithms / Filters 

• vtkAppendFilter 

• vtkAppendPolyData 

• vtkBooleanTexture 

• vtkBrownianPoints 

• vtkCastToConcrete 

• vtkCellCenters 

• vtkCellDataToPointData 

• vtkCullVisiblePoints 

• vtkCleanPolyData 

• vtkClipPolyData 

• vtkEdgePoints 

• vtkElevationFilter 

• vtkExtractEdges 

• vtkExtractGeometry 

• vtkExtractGrid 

• vtkExtractTensorComponent 

s 

• vtkExtractUnstructuredGrid 

• vtkExtractVOI 

• vtkExtractVectorComponents 

• vtkFeatureEdges… 

Vtk Chart API 

• Multiple chart types 

– Line plots 

– Bar graphs 

– Scatter plots 

– Area charts 

– Pie charts 

– Flood plots 

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VTK chart API 

Information Visualization in VTK 

• Titan project 2008 - collaborative effort 

between Sandia National Laboratories and 

Kitware Inc. 

• One of the first software development 

efforts to address the merging of scientific 

visualization and information visualization 

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VTK infoVis 

VTK infoVis 

vtkTable 

vtkDataObject 

vtkArray 

vtkGraph 

vtkTable 

vtkGraph (network) 

vtkDirectedGraph 

vtkTree (hierarchy) 

vtkDirectedAcyclicGraph 

vtkUndirectedGraph 

vtkArray 

vtkTree 

From: 

http://titan.sandia.gov/media/Information_Visualization_in_VTK.pdf 

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vtkMutableDirectedGraph 

vtkMutableUndirectedGraph 

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From: http://titan.sandia.gov/media/Information_Visualization_in_VTK.pdf 

VTK infoVis 

VTK infoVis 

AND MORE: 

– Data conversion 

– Database access 

– Graph algorithms 

– Statistics 

vtkGraphLayout 

vtkTreeMapView 


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Main advantages 

Main problems 

– Free 

– Easy creation of graphical applications 

– C++ source code available 

– Make learning of computer Graphics, 

Visualization and Image Processing easier. 

– Platform independent. 

– Large quantity of widgets for object 

manipulation 

– Integrate software (not a series of pieces of 

code). 

– Easy visualization of data 

– Object Oriented 

– Largely used in many commercial 

applications, almost standard 

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– Not very fast 

– Relatively heavy, need a reasonable machine 

– Documentation 

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Help 

3D Modelling and Visualization Course 

• VTK User’s Guide 

• The Visualization Toolkit TextBook 

• Doxygen Documentation 

• Kitware pages on VTK (examples, testing, 

etc…) 

FootVR 

3D Audio 

Brain Imaging 

Vectorial Data 

2D Audio 

Polygonal Meshes 

Cutting 

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Geoscience data 

RIR Acquisition 

Medical data 

Robotic simulators 

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VTK Installation 

• Download Cmake 

http://www.cmake.org/cmake/resources/softwar 

e.html 

• Download VTK 

http://www.vtk.org/VTK/resources/software.html 

VTK Installation - Cmake 

• Run Cmake -indicate source directory (VTK files) 

and where to build binaries. 

• Choose compiler (for example Visual Studio 9 – 

VS2008) 

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VTK Installation - Cmake 

• Configure compilation options, namely: 

– BUILS_SHARED_LIBS 

– VTK_WRAP_JAVA 

– CMAKE_INSTALL_PREFIX (directory for 

installation) 

– VTK_USE_CHARTS 

– VTK_USE_INFOVIS 

• Click on configure 

VTK Installation - Compilation 

• Open Project in Visual Studio (solution is in 

binary directory with name: vtk.sln) 

• Build all (take some time) 

• run install project to copy files to install directory 

• Add Install directory in path 

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VTK Installation – Visual Studio 

1. Indicate location of header files [configuration properties- 

>C/C++->General]. In [Additional Include Directories] include 

header file directory: [ex:”C:\Program Files\VTK\include\vtk“] 


2. Indicate location of library files [configuration properties->Linker- 

>Genera]. In [Additional Library Directories] include lib file 

directory: [ex:” C:\Program Files\VTK\lib“] 

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3. In Linker->Input->Additional Dependencies, include lib files: 

vtkCommon.lib vtkFiltering.lib vtkGraphics.lib vtkHybrid.lib 

vtkImaging.lib vtkIO.lib vtkjpeg.lib vtkpng.lib vtkRendering.lib vtkzlib.lib 

vtkWidgets.lib 

4. Add vtk DLL directory to the path. In windows can be done thorugh 

Control Panel->System->Advanced->Environment variables 

and rebooting computer 

VTK Installation - netbeans 

• Add vtk.jar to the project (right click, libraries). 

• Ensure that vtk DLL files are in the path. 

• Add the import to the JAVA file: 

System.loadLibrary("vtkCommonJava"); 

System.loadLibrary("vtkFilteringJava"); 

System.loadLibrary("vtkViewsJava"); 

System.loadLibrary("vtkImagingJava"); 

System.loadLibrary("vtkInfovisJava"); 

System.loadLibrary("vtkGraphicsJava"); 

System.loadLibrary("vtkRenderingJava"); 

In VTK (5.8.1), Java wrapping is missing for 

vtkChart API. To create the wrapper, copy vtk.jar 

to vtk.zip, unzip the file, and run javac *.java inside 

the unzipped file to wrap all the classes for JAVA, 

the zip the files into vtk.jar again. 

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Diapositivo 1 - Sweet - Universidade de Aveiro

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