scientific visualization using vtk robert putnam [email protected] scientific visualization with vtk –...

Scientific Visualization using VTKScientific Visualization using VTK

Robert Putnam

[email protected]

Scientific Visualization with VTK – Fall 2010

OutlineOutline

• Introduction• VTK overview• VTK data geometry/topology• Case study• Interactive session


IntroductionIntroduction


*Adapted from The ParaView Tutorial, Moreland

• Visualization: converting raw data to a form that is viewable and understandable to humans.

• Scientific visualization: specifically concerned with data that has a well-defined representation in 2D or 3D space (e.g., from simulation mesh or scanner).

VTKVTK

Visualization Toolkit– Open source

– Set of object-oriented class libraries for visualization and data analysis

– Several language interfaces• C++

• Tcl

• Java

• Python

– Portable (MS Windows, Linux, OSX)

– Active developer community

– Good documentation available, free and otherwise

– Professional support services available from Kitware


Generic visualization pipelineGeneric visualization pipeline


Source(s) Filters(s) Output - - - - - - - - - - - - - - - - - - - - -

data/geometry/topology graphics

VTK terminology/modelVTK terminology/model


Source Filter Renderer

- - - - - - - - - - - - - - - - - - - - -


Mapper

VTK terminology/modelVTK terminology/model


Source/ Reader

Filter Renderer

- - - - - - - - - - - - - - - - - - - - -


Mapper

“Scene"

Lights, Camera

DataObject ProcessObject

Actor

RenderWindow

Pipeline -> Sample CodePipeline -> Sample CodevtkStructuredGridReader reader

reader SetFileName "density.vtk"

reader Update

vtkContourFilter iso

iso SetInputConnection [reader GetOutputPort]

iso SetValue 0 .26

vtkPolyDataMapper isoMapper

isoMapper SetInputConnection [iso GetOutputPort]

vtkActor isoActor

isoActor SetMapper isoMapper

vtkRenderer ren1

ren1 AddActor isoActor

vtkRenderWindow renWin

renWin AddRenderer ren1

renWin SetSize 500 500

renWin Render


Reader

Filter

Mapper

Actor

Renderer

RenderWindow

TCL v. C++TCL v. C++

• TCL

• C++


vtkStructuredGridReader reader

reader SetFileName "density.vtk"

reader Update



iso SetValue 0 .26

vtkStructuredGridReader *reader = vtkStructuredGridReader::New();reader->SetFileName("density.vtk");reader->Update();

vtkContourFilter *iso = vtkCountourFilter::New();iso->SetInputConnection(reader->GetOutputPort());iso->SetValue(0, .26);

Coding tip of the day!Coding tip of the day!

• Google “VTK class list”, or• Go to:

http://www.vtk.org/doc/nightly/html/annotated.html


VTK – Geometry v. TopologyVTK – Geometry v. Topology

Geometry of a dataset ~= points


0,1 1,1 2,1 3,1

0,0 1,0 2,0 3,0

Topology ~= connections among points, which define cells

So, what’s the topology here?



0,1 1,1 2,1 3,1

0,0 1,0 2,0 3,0



0,1 1,1 2,1 3,1

0,0 1,0 2,0 3,0

or

0,1 1,1 2,1 3,1

0,0 1,0 2,0 3,0



or

0,1 1,1 2,1 3,1

0,0 1,0 2,0 3,0

0,1 1,1 2,1 3,1

0,0 1,0 2,0 3,0

or

0,1 1,1 2,1 3,1

0,0 1,0 2,0 3,0



or

0,1 1,1 2,1 3,1

0,0 1,0 2,0 3,0

or

0,1 1,1 2,1 3,1

0,0 1,0 2,0 3,0

0,1 1,1 2,1 3,1

0,0 1,0 2,0 3,0

or

0,1 1,1 2,1 3,1

0,0 1,0 2,0 3,0

Geometry/Topology StructureGeometry/Topology Structure

Structure may be regular or irregular– Regular (structured)

• need to store only beginning position, spacing, number of points

• smaller memory footprint per cell (topology can be generated on the fly)

• examples: image data, rectilinear grid, structured grid

– Irregular (unstructured)• information can be represented more densely where it changes quickly

• higher memory footprint (topology must be explicitly written) but more freedom

• examples: polygonal data, unstructured grid


Characteristics of DataCharacteristics of Data

Data is organized into datasets for visualization– Datasets consist of two pieces

• organizing structure– points (geometry)

– cells (topology)

• data attributes associated with the structure

– File format derived from organizing structure


Data is discrete– Interpolation functions generate data values in between known points

Examples of Dataset TypesExamples of Dataset Types

Structured Points (Image Data)– regular in both topology and geometry

– examples: lines, pixels, voxels

– applications: imaging CT, MRI

Rectilinear Grid– regular topology but geometry only partially

regular

– examples: pixels, voxels

Structured Grid (Curvilinear)– regular topology and irregular geometry

– examples: quadrilaterals, hexahedron

– applications: fluid flow, heat transfer


Examples of Dataset Types (cont)Examples of Dataset Types (cont)

Polygonal Data– irregular in both topology and geometry

– examples: vertices, polyvertices, lines, polylines, polygons, triangle strips

Unstructured Grid – irregular in both topology and geometry

– examples: any combination of cells

– applications: finite element analysis, structural design, vibration


Examples of Cell TypesExamples of Cell Types


Data AttributesData Attributes

Data attributes associated with the organizing structure– Scalars

• single valued

• examples: temperature, pressure, density, elevation

– Vectors• magnitude and direction

• examples: velocity, momentum

– Normals • direction vectors (magnitude of 1) used for shading

– Texture Coordinates• used to map a point in Cartesian space into 1, 2, or 3D texture space

• used for texture mapping

– Tensors • 3x3 only

• examples: stress, strain


File Format – Structured PointsFile Format – Structured Points


Editor structured-points.vtk:

# vtk DataFile Version 3.0

first dataset

ASCII

DATASET STRUCTURED_POINTS

DIMENSIONS 3 4 5

ORIGIN 0 0 0

SPACING 1 1 2

POINT_DATA 60

SCALARS temp-point float

LOOKUP_TABLE default

0 0 0 1 1 1 1 1 1 0 0 0

0 0 0 1 1 1 1 1 1 0 0 0

0 0 0 1 1 1 1 1 1 0 0 0

0 0 0 1 1 1 1 1 1 0 0 0

0 0 0 1 1 1 1 1 1 0 0 0

File Format – Structured PointsFile Format – Structured Points


Editor structured-points2.vtk:

# vtk DataFile Version 3.0

first dataset

ASCII

DATASET STRUCTURED_POINTS

DIMENSIONS 3 4 5

ORIGIN 0 0 0

SPACING 1 1 2

CELL_DATA 24

SCALARS temp-cell float


0 0 1 1 0 0

0 0 1 1 0 0

0 0 1 1 0 0

0 0 1 1 0 0

Structured Points – Tcl codeStructured Points – Tcl code


Editor structured-points.tcl:vtkStructuredPointsReader reader

reader SetFileName "structured-points.vtk"

reader Update

vtkLookupTable lut

lut SetNumberOfColors 2

lut SetTableValue 0 0.0 0.0 1.0 1


vtkDataSetMapper mapper

mapper SetInputConnection [reader GetOutputPort]

mapper SetLookupTable lut

vtkActor actor

actor SetMapper mapper

[actor GetProperty] EdgeVisibilityOn

[actor GetProperty] SetLineWidth 2

Structured Points – Tcl code (cont.)Structured Points – Tcl code (cont.)


Editor structured-points.tcl:vtkRenderer ren1

ren1 AddActor actor

ren1 SetBackground 0.5 0.5 0.5




vtkRenderWindowInteractor iren

iren SetRenderWindow renWin

iren Initialize

wm withdraw .

Work flow – Case StudyWork flow – Case Study

BU Space Physics simulation Meteor trails in the ionosphere Data wrangling:

Consolidate datafiles (from parallel code), create single binary datafile

Add VTK header:


# vtk DataFile Version 3.0output of reassemble.cBINARYDATASET STRUCTURED_POINTSORIGIN 0.0 0.0 0.0SPACING 1.0 1.0 1.0DIMENSIONS 512 64 128POINT_DATA 4194304SCALARS plasma floatLOOKUP_TABLE default


Use Tcl for fast development/testing:


vtkStructuredPointsReader reader reader SetFileName "opp.vtk" reader Update

vtkContourFilter iso iso SetInputConnection \[reader GetOutputPort] iso SetValue 0 0.1

. . .


Add gaussian filter :


vtkImageGaussianSmooth gaussian gaussian SetInputConnection [reader GetOutputPort] gaussian SetDimensionality 3 gaussian SetRadiusFactor 1 vtkContourFilter iso iso SetInputConnection \ [gaussian GetOutputPort] iso SetValue 0 0.1

. . .


Add more isosurfaces :


vtkContourFilter iso iso SetInputConnection [gaussian GetOutputPort] iso SetValue 0 1.0 iso SetValue 1 0.5 iso SetValue 2 0.1


Port to C++, add cutplane, transparency :


vtkPlane *plane = vtkPlane::New(); plane->SetOrigin(256,2,63.5); plane->SetNormal(0,1,0);

vtkCutter *planeCut = vtkCutter::New(); planeCut->SetInputConnection(reader->GetOutputPort()); planeCut->SetCutFunction(plane);


Change color map, use script to loop over *.vtk, generate multiple jpegs, read into Adobe Premiere, produce animation:


VTK – Getting Started - UIVTK – Getting Started - UI


Unix Shell:

katana:% cd ~/materials

katana:% vtk cone2.tcl

Keyboard shortcutsKeyboard shortcuts


j – joystick (continuous) modet – trackball mode

c –camera move modea –actor move mode

left mouse – rotate x,yctrl - left mouse – rotate zmiddle mouse –panright mouse –zoom

r –reset cameras/w –surface/wireframeu –command windowe –exit

Code – cone2.tclCode – cone2.tcl


Editor cone2.tcl:vtkConeSource cone

cone SetResolution 100

vtkPolyDataMapper coneMapper

coneMapper SetInput [cone GetOutput]

vtkActor coneActor

coneActor SetMapper coneMapper

[coneActor GetProperty] SetColor 1.0 0.0 0.0

vtkRenderer ren1


ren1 AddActor coneActor






iren Initialize

ExerciseExercise


Editor: cone3.tcl

Add coneActor2, and color it green. (Copy

coneActor, and make appropriate changes.

Remember to add the new actor to the

render window [near the end of the

“pipeline”].)

Optional: to rotate, scale and set the position

away from the origin, use the following:

coneActor2 RotateZ 90

coneActor2 SetScale 0.5 0.5 0.5

coneActor2 SetPosition -1.0 0.0 0.0

Code – ExerciseCode – Exercise


Editor: cone3.tcl

. . .

vtkActor coneActor2

coneActor2 SetMapper coneMapper

[coneActor2 GetProperty] SetColor 0.0 1.0 0.0

coneActor2 RotateZ 90

coneActor2 SetScale 0.5 0.5 0.5

coneActor2 SetPosition -1.0 0.0 0.0

. . .

ren1 AddActor coneActor

ren1 AddActor coneActor2

. . .

VTK - ReadersVTK - Readers Image and Volume Readers

– vtkStructuredPointsReader - read VTK structured points data files

– vtkSLCReader - read SLC structured points files

– vtkTIFFReader - read files in TIFF format

– vtkVolumeReader - read image (volume) files

– vtkVolume16Reader - read 16-bit image (volume) files

Structured Grid Readers– vtkStructuredGridReader - read VTK structured grid data files

– vtkPLOT3DReader - read structured grid PLOT3D files

Rectilinear Grid Readers– vtkRectilinearGridReader - read VTK rectilinear grid data files

Unstructured Grid Readers– vtkUnstructuredGridReader - read VTK unstructured grid data files


VTK - ReadersVTK - Readers Polygonal Data Readers

– vtkPolyDataReader - read VTK polygonal data files

– vtkBYUReader - read MOVIE.BYU files

– vtkMCubesReader - read binary marching cubes files

– vtkOBJReader - read Wavefront (Maya) .obj files

– vtkPLYReader - read Stanford University PLY polygonal data files

– vtkSTLReader - read stereo-lithography files

– vtkUGFacetReader - read EDS Unigraphic facet files

Image and Volume Readers (add’l)– vtkBMPReader - read PC bitmap files

– vtkDEMReader - read digital elevation model files

– vtkJPEGReader - read JPEG files

– vtkImageReader - read various image files

– vtkPNMReader - read PNM (ppm, pgm, pbm) files

– vtkPNGRReader - read Portable Network Graphic files


File Format – Structured GridFile Format – Structured Grid


Editor density.vtk:# vtk DataFile Version 3.0

vtk output

ASCII

DATASET STRUCTURED_GRID

DIMENSIONS 57 33 25

POINTS 47025 float

2.667 -3.77476 23.8329 2.94346 -3.74825 23.6656 3.21986 -3.72175 23.4982

3.50007 -3.70204 23.3738 3.9116 -3.72708 23.5319 4.1656 -3.69529 23.3312

. . .

POINT_DATA 47025

SCALARS Density float


0.639897 0.239841 0.252319 0.255393 0.252118 0.246661 0.240134 0.234116 0.229199

0.225886 0.224268 0.224647 0.231496 0.246895 0.26417 0.27585 0.278987 0.274621

. . .

VECTORS Momentum float

0 0 0 13.753 -5.32483 -19.964 42.3106 -15.57 -43.0034

64.2447 -13.3958 -46.2281 73.7861 -4.83205 -36.3829 88.3374 6.23797 -22.8846

. . .

Clipping, Cutting, SubsamplingClipping, Cutting, Subsampling

Selection Algorithms - Clipping

• can reveal internal details of surface

• VTK - vtkClipDataSet

- Cutting/Slicing• cutting through a dataset with a surface

• VTK - vtkCutter

- Subsampling• reduces data size by selecting a subset of

the original data

• VTK - vtkExtractGrid


Code – ClippingCode – Clipping


Editor: clipping.tclvtkStructuredGridReader reader

reader SetFileName “density.vtk”

reader Update

vtkPlane plane

eval plane SetOrigin [[reader GetOutput] GetCenter]

plane SetNormal -0.287 0 0.9579

vtkClipDataSet clip

clip SetInputConnection [reader GetOutputPort]

clip SetClipFunction plane

clip InsideOutOn

vtkDataSetMapper clipMapper

clipMapper SetInputConnection [clip GetOutputPort]

eval clipMapper SetScalarRange [[reader GetOutput] GetScalarRange]

vtkActor clipActor

clipActor SetMapper clipMapper

Code – Cutplane/SlicingCode – Cutplane/Slicing


Editor: cutplane.tclvtkStructuredGridReader reader


reader Update

vtkPlane plane

eval plane SetOrigin [[reader GetOutput] GetCenter]

plane SetNormal -0.287 0 0.9579

vtkCutter planeCut

planeCut SetInputConnection

[reader GetOutputPort] planeCut SetCutFunction plane

vtkPolyDataMapper cutMapper

cutMapper SetInputConnection [planeCut GetOutputPort]

eval cutMapper SetScalarRange [[reader GetOutput] GetScalarRange]

vtkActor cutActor

cutActor SetMapper cutMapper

Code – ExtractGridCode – ExtractGrid


Editor: extract.tclvtkStructuredGridReader reader


reader Update

vtkExtractGrid extract

extract SetInputConnection [reader GetOutputPort]

extract SetVOI -1000 1000 -1000 1000 7 10

extract SetSampleRate 1 1 1

extract IncludeBoundaryOn


mapper SetInputConnection [extract GetOutputPort]

eval mapper SetScalarRange [[reader GetOutput] GetScalarRange]

vtkActor extractActor

extractActor mapper

Color MappingColor Mapping

Scalar Algorithms– Color Mapping

• maps scalar data to colors

• implemented by using scalar values as an index into a color lookup table

• specify a HSVA (Hue-Saturation-Value-Alpha) ramp and then generate the colors in the table by using linear interpolation into the HSVA space.

– VTK • vtkLookupTable

• vtkDataSetMapper


Code – Color MappingCode – Color Mapping


Editor: colormap.numcolors.tcl

. . .

vtkLookupTable lut

lut SetNumberofColors 16

lut SetHueRange 0.0 0.667

lut Build


reader SetFileName “subset.vtk”

reader Update


mapper SetInputConnection [reader GetOutputPort]

mapper SetLookupTable lut

eval mapper SetScalarRange [[reader GetOutput] GetScalarRange]

vtkActor actor

actor SetMapper mapper

. . .

ExerciseExercise


* Change the number of colors in colormap

* Reverse the Hue Range

* Change the Scalar Range

mapper SetScalarRange 0.0 0.7

ContouringContouring

Scalar Algorithms (cont)– Contouring

• construct a boundary between distinct regions, two steps:– explore space to find points near contour

– connect points into contour (2D) or surface (3D)

• 2D contour map (isoline):– applications: elevation contours from topography, pressure contours

(weather maps) from meteorology3D isosurface:

• 3D isosurface:– applications: tissue surfaces from tomography, constant pressure or

temperature in fluid flow, implicit surfaces from math and CAD

– VTK• vtkContourFilter


Code – Contour (isoline)Code – Contour (isoline)


Editor: contour.single.tcl

. . .


reader SetFileName “subset.vtk”

reader Update

vtkContourFilter contour

contour SetInputConnection [reader GetOutputPort]

contour SetValue 0 0.26

vtkPolyDataMapper contourMapper

contourMapper SetInputConnection [contour GetOutputPort]

eval contourMapper SetScalarRange

[[reader GetOutput] GetScalarRange]

vtkActor contourActor

contourActor SetMapper contourMapper

. . .

Code – Contour (isosurface)Code – Contour (isosurface)


Editor: isosurface.tcl

. . .



reader Update



iso SetValue 0 0.26

vtkPolyDataMapper isoMapper

isoMapper SetInputConnection [iso GetOutputPort]

eval isoMapper SetScalarRange [[reader GetOutput] GetScalarRange]

vtkActor isoActor

isoActor SetMapper isoMapper

. . .

Scalar GenerationScalar Generation

Scalar Algorithms (cont)– Scalar Generation

• extract scalars from part of data

• example: extracting z coordinate (elevation) from terrain data to create scalar values

– VTK• vtkElevationFilter


Code – Scalar GenerationCode – Scalar Generation


Editor: hawaii.color.tclvtkPolyDataReader hawaii

hawaii SetFileName "honolulu.vtk"

hawaii Update

vtkElevationFilter elevation

elevation SetInput [hawaii GetOutput]

elevation SetLowPoint 0 0 0

elevation SetHighPoint 0 0 1000

elevation SetScalarRange 0 1000

vtkLookupTable lut

lut SetHueRange 0.7 0

vtkDataSetMapper hawaiiMapper

hawaiiMapper SetInput [elevation GetOutput]

hawaiiMapper SetScalarRange 0 1000

hawaiiMapper SetLookupTable lut

vtkActor hawaiiActor

hawaiiActor SetMapper hawaiiMapper

Scalar generation – Color MapScalar generation – Color Map


Editor: hawaii.color2.tclvtkLookupTable lut

lut SetNumberOfColors 9

lut SetTableValue 0 0 0.4 0.8 1








lut SetTableValue 8 1.0 1 1 1

HedgehogsHedgehogs

Vector Algorithms– Hedgehogs

• oriented scaled line for each vector

• scale indicates magnitude

• color indicates magnitude, pressure, temperature, or any variable

– VTK• vtkHedgeHog


Code – HedgeHogsCode – HedgeHogs


Editor: hedgehog.tclvtkStructuredGridReader reader


reader Update

vtkHedgeHog hhog

hhog SetInput [reader GetOutput]

hhog SetScaleFactor 0.001

vtkPolyDataMapper hhogMapper

hhogMapper SetInput [hhog GetOutput]

hhogMapper SetLookupTable lut

eval hhogMapper SetScalarRange [[reader GetOutput] GetScalarRange]

vtkActor hhogActor

hhogActor SetMapper hhogMapper

Oriented GlyphsOriented Glyphs

Vector Algorithms (cont)– Oriented Glyphs

• orientation indicates direction

• scale indicates magnitude

• color indicates magnitude, pressure, temperature, or any variable

– VTK• vtkGlyph3D


Code – Oriented GlyphsCode – Oriented Glyphs


Editor: glyph.tclvtkArrowSource arrow

arrow SetTipResolution 6

arrow SetTipRadius 0.1

arrow SetTipLength 0.35

arrow SetShaftResolution 6

arrow SetShaftRadius 0.03

vtkGlyph3D glyph

glyph SetInput [reader GetOutputPort]

glyph SetSource [arrow GetOutputPort]

glyph SetVectorModeToUseVector

glyph SetColorModeToColorByScalar

glyph SetScaleModeToDataScalingOff

glyph OrientOn

glyph SetScaleFactor 0.2

vtkPolyDataMapper glyphMapper

glyphMapper SetInput [glyph GetOutput]

glyphMapper SetLookupTable lut

glyphMapper ScalarVisibilityOn

eval glyphMapper SetScalarRange [[reader GetOutput] GetScalarRange]

Field LinesField Lines

Vector Algorithms (cont)– Field Lines

• Fluid flow is described by a vector field in three dimensions for steady (fixed time) flows or four dimensions for unsteady (time varying) flows

• Three techniques for determining flow– Pathline (Trace)

• tracks particle through unsteady (time-varying) flow

• shows particle trajectories over time

• rake releases particles from multiple positions at the same time instant

• reveals compression, vorticity

– Streamline

• tracks particle through steady (fixed-time) flow

• holds flow steady at a fixed time

• snapshot of flow at a given time instant

– Streakline

• particles released from the same position over a time interval (time-varying)

• snapshot of the variation of flow over time

• example: dye steadily injected into fluid at a fixed point


Field LinesField LinesStreamlines

• Lines show particle flow

• VTK – vtkStreamTracer

Streamlets• half way between streamlines and glyphs

• VTK - vtkStreamTracer, vtkGlyph3D

Streamribbon• rake of two particles to create a ribbon

• VTK - vtkStreamTracer, vtkRuledSurfaceFilter

Streamtube• circular rake of particles to create a tube

• VTK - vtkStreamTracer, vtkTubeFilter


Code – StreamlinesCode – Streamlines


Editor: streamLines.tclvtkPointSource seeds

seeds SetRadius 3.0

eval seeds SetCenter [[reader GetOutput] GetCenter]

seeds SetNumberOfPoints 100

vtkRungeKutta4 integ

vtkStreamTracer streamer

streamer SetInputConnection [reader GetOutputPort]

streamer SetSourceConnection [seeds GetOutputPort]

streamer SetMaximumPropagation 100

streamer SetMaximumPropagationUnitToTimeUnit

streamer SetInitialIntegrationStepUnitToCellLengthUnit

streamer SetInitialIntegrationStep 0.1

streamer SetIntegrationDirectionToBoth

streamer SetIntegrator integ

vtkPolyDataMapper mapStreamLines

mapStreamLines SetInputConnection [streamer GetOutputPort]

eval mapStreamLines SetScalarRange [[reader GetOutput] GetScalarRange]

vtkActor streamLineActor

streamLineActor SetMapper mapStreamLines

Code – StreamtubesCode – Streamtubes


Editor: streamTubes.varyRadius.tclvtkPointSource seeds

seeds SetRadius 1.0

seeds SetNumberOfPoints 50

vtkRungeKutta4 integ

vtkStreamTracer streamer

streamer SetInputConnection [reader GetOutputPort]

streamer SetSourceConnection [seeds GetOutputPort]

. . .

vtkTubeFilter streamTube

streamTube SetInputConnection [streamer GetOutputPort]

streamTube SetRadius 0.01

streamTube SetNumberOfSides 6

# streamTube SetVaryRadiusToVaryRadiusOff

streamTube SetVaryRadiusToVaryRadiusByScalar

vtkPolyDataMapper mapStreamTube

mapStreamTube SetInputConnection [streamTube GetOutputPort]

mapStreamTube SetLookupTable lut

eval mapStreamTube SetScalarRange [[[[reader GetOutput] GetPointData] GetScalars] GetRange]

vtkActor streamTubeActor

streamTubeActor SetMapper mapStreamTube

[streamTubeActor GetProperty] BackfaceCullingOn

AnnotationAnnotation

Annotation– used for annotating visualization

– VTK• vtkScalarBarActor

• vtkTextMapper

• vtkScaledTextActor


Code – colorBarCode – colorBar


Editor: colorBar.tclvtkStructuredGridReader reader


reader Update

vtkScalarBarActor scalarBar

scalarBar SetLookupTable lut

scalarBar SetTitle "Combustor Density Magnitude"

scalarBar SetNumberOfLabels 2

[scalarBar GetPositionCoordinate] SetValue 0.1 0.01

scalarBar SetOrientationToHorizontal

scalarBar SetWidth 0.8

scalarBar SetHeight 0.09

vtkRenderer ren1





ren1 AddActor streamTubeActor

ren1 AddActor outlineActor

ren1 AddActor scalarBar


VTK - WritersVTK - Writers Polygonal Data Writers

– vtkBYUWriter - write MOVIE.BYU files

– vtkCGMWriter - write 2D polygonal data as a CGM file

– vtkIVWriter - write Inventor files

– vtkMCubesWriter - write triangles in marching cubes format

– vtkPolyDataWriter - write VTK polygonal data files

– vtkPLYWriter - write Standford University PLY polygonal data files

– vtkSTLWriter - write stereo-lithography files

Image and Volume writers– vtkBMPwriter - write PC bitmap files

– vtkJPEGwriter - write images in JPEG format

– vtkPostscriptWriter – write image files in Postscript format

– vtkPNMwriter - write PNM (ppm, pgm, pbm) image files

– vtkPNGwriter - write image file in Portable Network Graphic format

– vtkTIFFWriter – write image files in TIFF format

– vtkStructuredPointsWriter – write a vtkStructuredPoints file


Saving ImagesSaving Images

Saving Images– common formats:

• jpeg (lossy)

• png (lossless)

• postscript

• tiff (lossless)

– VTK•vtkWindowToImageFilter

•vtkRenderLargeImage


Code – Saving ImagesCode – Saving Images


Editor: output.tclrenWin Render

vtkWindowToImageFilter w2if

w2if SetInput renWin

w2if Update

vtkRenderLargeImage renderLarge

renderLarge SetInput ren1

renderLarge SetMagnification 4

#vtkJPEGWriter writer

# writer SetInputConnection [w2if GetOutputPort]

# writer SetFileName "image.jpg"

# writer SetQuality 100

# writer Write

#vtkPNGWriter writer


# writer SetFileName "image.png"

# writer Write

#vtkPostScriptWriter writer


# writer SetFileName "image.ps"

# writer Write

#vtkTIFFWriter writer


# writer SetFileName "image.tif"

# writer Write

vtkTIFFWriter lwriter

lwriter SetInputConnection [renderLarge GetOutputPort]

lwriter SetFileName "largeimage.tif"

lwriter Write

VTK - ResourcesVTK - Resources


IS&T tutorials– Scientific Visualization with VTK

www.bu.edu/tech/research/training/tutorials/vtk/

– VTK Examples

www.bu.edu/tech/research/training/scv-software-packages/vtk/vtk_examples/

Texts– The Visualization Toolkit, 4th Edition, Kitware, Inc, 2006.

– The VTK User’s Guide, 5th Edition, Kitware, Inc, 2006.

Websites– www.vtk.org

– www.kitware.com

– www.vtk.org/doc/release/5.4/html/classes.html

Wiki– www.vtk.org/Wiki/VTK

Mailing Lists– www.vtk.org/VTK/help/mailing.html

Questions?Questions?

Tutorial survey:

- http://scv.bu.edu/survey/fall10tut_survey.html


scientific visualization using vtk robert putnam [email protected] scientific visualization with vtk –...

Documents