PythonicAPI Examples¶

These examples use the improved VTK Python interface. Some information about the improved Python interface can be found here

The examples here are either newly crafted ones or upgraded existing Python examples using the improved VTK Python interface.

See More Pythonic VTK wrapping for the VTK Discourse discussion and Wrap VTK properties to pythonic properties with snake_case names for the merge request.

Upgrading an existing example to use the improved VTK Python interface¶

1. Copy the example from the src/Python folder into the src/PythonicAPI folder maintaining the same path structure. If there is a corresponding markdown file, copy it.
2. Copy the corresponding test image from src/Testing/Baseline/Python/ into src/Testing/Baseline/PythonicAPI/
3. Edit src/PythonicAPI.md, possibly creating a table and headings to match the original example in src/Python.
4. Upgrade the Python example.
5. The associated markdown file (if any) may need checking to ensure any links in the document remain valid.
6. Check everything is working and do a Merge Request.

Adding a new example¶

Follow the documented procedure ForDevelopers remembering that the folder to use is PythonicAPI.

VTK Classes Summary¶

This Python script, SelectExamples, will let you select examples based on a VTK Class and language. It requires Python 3.7 or later. The following tables will produce similar information.

• VTK Classes with Examples, this table is really useful when searching for example(s) using a particular class.

• VTK Classes with No Examples, please add examples in your area of expertise!

Tutorials¶

Hello World¶

Example Name	Description	Image
A hello world example	Cylinder example from the VTK Textbook and source code. A hello world example.

Simple Operations¶

Input and Output¶

Graph Formats¶

3D File Formats¶

Standard Formats¶

Input¶

Example Name	Description	Image
ReadAllPolyDataTypesDemo	Read all VTK polydata file types.
ReadExodusData	A simple script for reading and viewing ExodusII data interactively.

Importers¶

Output¶

VTK Formats¶

Input¶

Output¶

Legacy VTK Formats¶

Example Name	Description	Image
ReadLegacyUnstructuredGrid	Read an unstructured grid that contains 11 linear cells.

Image Format¶

Input¶

Example Name	Description	Image
HDRReader	Read a high-dynamic-range imaging file.

Output¶

Geometric Objects¶

Example Name	Description	Image
GeometricObjectsDemo
PipelineReuse	How to reuse a pipeline.
SourceObjectsDemo	Examples of source objects that procedurally generate polygonal models. These nine images represent just some of the capability of VTK. From upper left in reading order: sphere, cone, cylinder, cube, plane, text, random point cloud, disk (with or without hole), and line source. Other polygonal source objects are available; check subclasses of vtkPolyDataAlgorithm.

Cells¶

Sources¶

Non Linear¶

Parametric Objects¶

Example Name	Description	Image
ParametricObjectsDemo	Demonstrates the Parametric classes added by Andrew Maclean and additional classes added by Tim Meehan. The parametric spline is also included. Options are provided to display single objects, add backface, add normals and print out an image.
ParametricKuenDemo	Interactively change the parameters for a Kuen Surface.

Implicit Functions and Iso-surfaces¶

Example Name	Description	Image
BooleanOperationImplicitFunctions	Demonstrate booleans of two different implicit functions
DiscreteFlyingEdges3D	Generate surfaces from labeled data.
ImplicitQuadric	Create an ellipsoid using an implicit quadric
ImplicitSphere	Demonstrate sampling of a sphere implicit function
ImplicitSphere1	Demonstrate sampling of a sphere implicit function
SampleFunction	Sample and visualize an implicit function.
SmoothDiscreteFlyingEdges3D	Generate smooth surfaces from labeled data.

Working with 3D Data¶

Example Name	Description	Image
AlignTwoPolyDatas	Align two vtkPolyData's.
BooleanPolyDataFilters	This example performs a boolean operation (intersection, union or difference) of two PolyData using either a vtkBooleanOperationPolyDataFilter or a vtkLoopBooleanPolyDataFilter
ConnectivityFilter	Color any dataset type based on connectivity.
Curvatures	Compute Gaussian, and Mean Curvatures.
CurvaturesAdjustEdges	Get the Gaussian and Mean curvatures of a surface with adjustments for edge effects.
ExtractPolyLinesFromPolyData	Extract polylines from polydata.
ExtractSelection	Extract selected points.
ExtractSelectionCells	Extract cell, select cell.
LineOnMesh	Plot a spline on a terrain-like surface.
MeshLabelImageColor	Mesh a single label from a label image. Then smooth and color the vertices according to the displacement error introduced by the smoothing.
SmoothMeshGrid	Create a terrain with regularly spaced points and smooth it with vtkLoopSubdivisionFilter and vtkButterflySubdivisionFilter.

Data Types¶

Example Name	Description	Image
OverlappingAMR	Demonstrates how to create and populate VTK's Overlapping AMR Grid type with data.

Data Type Conversions¶

Point Cloud Operations¶

Working with Meshes¶

This section includes examples of manipulating meshes.

Example Name	Description	Image
DelaunayMesh	Two-dimensional Delaunay triangulation of a random set of points. Points and edges are shown highlighted with sphere glyphs and tubes.

Clipping¶

Example Name	Description	Image
SolidClip	Create a "solid" clip. The "ghost" of the part clipped away is also shown.

Working with Structured 3D Data¶

vtkImageData¶

Example Name	Description	Image
ImageWeightedSum	Add two or more images.

vtkExplicitStructuredGrid¶

Example Name	Description	Image
CreateESGrid	Create an explicit structured grid and convert this to an unstructured grid or vice versa.
LoadESGrid	Load a VTU file and convert the dataset to an explicit structured grid.

vtkStructuredGrid¶

Example Name	Description	Image
BlankPoint	Blank a point of a vtkStructuredGrid.
SGrid	Creating a structured grid dataset of a semi-cylinder. Vectors are created whose magnitude is proportional to radius and oriented in tangential direction.

vtkStructuredPoints¶

Example Name	Description	Image
Vol	Creating a image data dataset. Scalar data is generated from the equation for a sphere. Volume dimensions are 26 x 26 x 26.

vtkRectilinearGrid¶

Example Name	Description	Image
RGrid	Creating a rectilinear grid dataset. The coordinates along each axis are defined using an instance of vtkDataArray.
VisualizeRectilinearGrid	Visualize the cells of a rectilinear grid.

Working with Unstructured 3D Data¶

This section includes vtkUnstructuredGrid.

vtkUnstructuredGrid¶

Registration¶

Medical¶

Example Name	Description	Image
MedicalDemo1	Create a skin surface from volume data.

Surface reconstruction¶

Utilities¶

Example Name	Description	Image
CheckVTKVersion	Check the VTK version and provide alternatives for different VTK versions.
ClassesInLang1NotInLang2	Select VTK classes with corresponding examples in one language but not in another.
ColorMapToLUT_JSON	Take a JSON description of a colormap and convert it to a VTK colormap.
ColorMapToLUT_XML	Take an XML description of a colormap and convert it to a VTK colormap.
ColorMapToLUT	Use vtkDiscretizableColorTransferFunction to generate a VTK colormap.
RescaleReverseLUT	Demonstrate how to adjust a colormap so that the colormap scalar range matches the scalar range on the object. You can optionally reverse the colors.
ResetCameraOrientation	Reset camera orientation to a previously saved orientation.
SaveSceneToFieldData	Save a vtkCamera's state in a vtkDataSet's vtkFieldData and restore it.
SaveSceneToFile	Save a vtkCamera's state in a file and restore it.
Screenshot
SelectExamples	Given a VTK Class and a language, select the matching examples.
ShareCamera	Share a camera between multiple renderers.
VTKWithNumpy

Arrays¶

Events¶

Math Operations¶

Graphs¶

Example Name	Description	Image
SideBySideGraphs	Display two graphs side by side.

Graph Conversions¶

Data Structures¶

Timing Demonstrations¶

KD-Tree¶

Oriented Bounding Box (OBB) Tree¶

Octree¶

Modified BSP Tree¶

HyperTreeGrid¶

Example Name	Description	Image
HyperTreeGridSource	Create a vtkHyperTreeGrid.

VTK Concepts¶

Rendering¶

Example Name	Description	Image
ColoredSphere	A simple sphere.
GradientBackground	Demonstrates the background shading options.
PBR_Skybox	Demonstrates physically based rendering, a skybox and image based lighting.
PBR_Skybox_Texturing	Demonstrates physically based rendering, a skybox, image based lighting and texturing.
PBR_Skybox_Anisotropy	Demonstrates physically based rendering, a skybox, image based lighting, and anisotropic texturing.
TransformSphere	The addition of a transform filter to ColoredSphere.

Lighting¶

Texture Mapping¶

Example Name	Description	Image
AnimateVectors	One frame from a vector field animation using texture maps.
TextureCutQuadric	Cut a quadric with boolean textures.
TextureCutSphere	Examples of texture thresholding using a boolean combination of two planes to cut nested spheres.
TexturePlane	Example of texture mapping.
TextureThreshold	Demonstrate the use of scalar thresholds to show values of flow density on three planes.

Tutorial¶

If you are new to VTK then these tutorials will help to get you started.

Visualization¶

See this tutorial for a brief explanation of the VTK terminology of mappers, actors, etc.

Example Name	Description	Image
AnnotatedCubeActor	Annotated cube.
AssignCellColorsFromLUT	Demonstrates how to assign colors to cells in a vtkPolyData structure using lookup tables.
ColoredAnnotatedCube	How to color the individual faces of an annotated cube.
CurvaturesNormalsElevations	Gaussian and Mean curvatures of a surface with arrows colored by elevation to display the normals.
QuadricVisualization	Visualizing a quadric function.
WarpCombustor	Carpet plots of combustor flow energy in a structured grid. Colors and plane displacement represent energy values.

Working with vtkImageData¶

Example Name	Description	Image
ImageNormalize	Normalize an image.

Volume Rendering¶

User Interaction¶

Example Name	Description	Image
CallBack	Setting up a callback with client data. Two different methods are demonstrated.
CellPicking	Cell Picking.
HighlightPickedActor	Pick and highlight an actor based on mouse clicks.
HighlightWithSilhouette	Highlight a picked actor by adding a silhouette.
InteractorStyleTrackballActor
InteractorStyleTrackballCamera
MouseEvents	Subclass the interactor style.
MouseEventsObserver	Use an observer.

Working with Images¶

Example Name	Description	Image
BackgroundImage	Display an image as the "background" of a scene, and render a superquadric in front of it.

Image Processing¶

Example Name	Description	Image
Attenuation	This MRI image illustrates attenuation that can occur due to sensor position. The artifact is removed by dividing by the attenuation profile determined manually.
EnhanceEdges	High-pass filters can extract and enhance edges in an image. Subtraction of the Laplacian (middle) from the original image (left) results in edge enhancement or a sharpening operation (right).
GaussianSmooth	Low-pass filters can be implemented as convolution with a Gaussian kernel.
VTKSpectrum	The discrete Fourier transform changes an image from the spatial domain into the frequency domain, where each pixel represents a sinusoidal function. This figure shows an image and its power spectrum displayed using a logarithmic transfer function.

Widgets¶

Plotting¶

Example Name	Description	Image
MultiplePlots	Display multiple plots by using viewports in a single render window.
ScatterPlot	Scatter plot.
SpiderPlot	Spider plot.

Animation¶

Example Name	Description	Image
Animation	Move a sphere across a scene.

Annotation¶

Example Name	Description	Image
TextOrigin	This example demonstrates the use of vtkVectorText and vtkFollower. vtkVectorText is used to create 3D annotation.

InfoVis¶

PyQt¶