mayavi2 - Man Page

A scientific visualization package for 2-D and 3-D data

Synopsis

mayavi2 [options] [args]

Where arg1, arg2 etc. are optional file names that correspond to saved Mayavi2 visualizations (filename.mv2), Mayavi2 scripts (filename.py) and any data file formats that Mayavi supports.

Description

Mayavi2 is a tool for 2-D and 3-D scientific visualization. Features of Mayavi2 include:

Visualization of scalar and vector data in 2 and 3 dimensions
Easy scriptability using Python
Easy extendability via sources, components, modules, and data filters
Reading several file formats: VTK (legacy and XML), PLOT3D, etc.
Saving of visualizations
Saving rendered visualization in a variety of image formats.

Options

-h: This prints all the available command line options and exits. Also available through --help.
-V: This prints the Mayavi version on the command line and exits. Also available through --version.
-z filename.mv2: This loads a previously saved Mayavi2 visualization. Also available through --viz filename.mv2 or --visualization filename.mv2.
-d: datafile.*

Opens any of the supported data file formats or a non-file related data source. This includes VTK file formats (*.vtk, *.xml, *.vt[i,p,r,s,u], *.pvt[i,p,r,s,u]), VRML2 (*.wrl), 3D Studio (*.3ds), PLOT3D (*.xyz), STL, BYU, RAW, PLY, PDB, SLC, FACET, OBJ, AVSUCD (*.inp), GAMBIT (*.neu), Exodus (*.exii), PNG, JPEG, BMP, PNM, DCM, DEM, MHA, MHD, MINC, XIMG, TIFF, and various others that are supported. datafile.* can also be a source object not associated with a file, for example ParametricSurface or PointLoad will load the corresponding data sources into Mayavi. Also available through --data.

-m: module-name

A module is an object that actually visualizes the data. The given module-name is loaded in the current ModuleManager. The module name must be a valid one if not you will get an error message.

If a module is specified as 'package.sub.module.SomeModule' then the module (SomeModule) is imported from 'package.sub.module'. Standard modules provided with mayavi2 do not need the full path specification. For example:

mayavi2 -d data.vtk -m Outline -m m2_user_modules.TestModule

In this example 'Outline' is a standard module and 'm2_user_modules.TestModule' is some user defined module. See Mayavi2 Modules section below for an exhaustive list of available modules. Also available through --module.

-f: filter-name

A filter is an object that filters out the data in some way or the other. The given filter-name is loaded with respect to the current source/filter object. The filter name must be a valid one if not you will get an error message.

If the filter is specified as 'package.sub.filter.SomeFilter' then the filter (`SomeFilter`) is imported from 'package.sub.filter'. Standard modules provided with mayavi2 do not need the full path specification. For example:

mayavi2 -d data.vtk -f ExtractVectorNorm -f m2_user_filters.TestFilter

In this example 'ExtractVectorNorm' is a standard filter and 'm2_user_filters.TestFilter' is some user defined filter.

See Mayavi2 Filters section below for an exhaustive list of available filters. Also available through --filter.

-M: Starts up a new module manager on the Mayavi pipeline. Also available through --module-mgr.
-n: Creates a new window/scene. Any options passed after this will apply to this newly created scene. Also available through --new-window.
-t: Runs the mayavi2 test suite and exits. If run as such, this runs both the TVTK and Mayavi2 unittests. If any additional arguments are passed they are passed along to the test runner. So this may be used to run other tests as well. For example:

mayavi2 -t enthought.persistence

This will run just the tests inside the enthought.persistence package. You can also specify a directory with test files to run with this, for example:

mayavi2 -t relative_path_to/integrationtests/mayavi

will run the integration tests from the mayavi sources. Also available through --test.

-x: script-file

This executes the given script in a namespace where we guarantee that the name 'mayavi' is Mayavi's script instance -- just like in the embedded Python interpreter. Also available through --exec

WARNING: Note that this uses `execfile`, so please note that this can be dangerous if the script does something nasty!

-s: python-expression

Execute the expression on the last created object. For example, if the previous object was a module, and we want to set the color of that object one can do -s "actor.property.color = (1,0,0)". One should use quotes for the expression. Also available with --set. For example:

mayavi2 -d ParametricSurface -m Outline \
-s "actor.property.color = (1,0,0)" \
-s "scene.save('test.png', size=(800, 800))"

WARNING: Note that this uses `exec`, so please note that this can be dangerous!

Mayavi2 Modules

Axes: Draws simple axes.
ContourGridPlane: A contour grid plane module. This module lets one take a slice of input grid data and view contours of the data.
CustomGridPlane: A custom grid plane with a lot more flexibility than GridPlane module.
DataSetClipper: This filter clips the dataset in a area. The area can be defined interactively as a box, a sphere...
Glyph: Displays different types of glyphs oriented and colored as per scalar or vector data at the input points.
GridPlane: A simple grid plane module.
HyperStreamline: A module that integrates through a tensor field to generate a hyperstreamline. The integration is along the maximum eigenvector and the cross section of the hyperstreamline is defined by the two other eigenvectors. Thus the shape of the hyperstreamline is "tube-like", with the cross section being elliptical. Hyperstreamlines are used to visualize tensor fields.
ImageActor: A simple module to view image data efficiently.
ImagePlaneWidget: A simple module to view image data.
IsoSurface: A module that allows the user to make contours of input point data.
Labels: Allows a user to label the current dataset or the current actor of the active module.
OrientationAxes: Creates a small axes on the side that indicates the position of the co-ordinate axes and thereby marks the orientation of the scene. Requires VTK-4.5 and above.
Outline: A module that draws an outline for the given data.
ScalarCutPlane: Takes a cut plane of any input data set using an implicit plane and plots the data with optional contouring and scalar warping.
SliceUnstructuredGrid: This module takes a slice of the unstructured grid data and shows the cells that intersect or touch the slice.
Streamline: Allows the user to draw streamlines for given vector data. This supports various types of seed objects (line, sphere, plane and point seeds). It also allows the user to draw ribbons or tubes and further supports different types of interactive modes of calculating the streamlines.
StructuredGridOutline: Draws a grid-conforming outline for structured grids.
Surface: Draws a surface for any input dataset with optional contouring.
TensorGlyph: Displays tensor glyphs oriented and colored as per scalar or vector data at the input points.
Text: This module allows the user to place text on the screen.
VectorCutPlane: Takes an arbitrary slice of the input data using an implicit cut plane and places glyphs according to the vector field data. The glyphs may be colored using either the vector magnitude or the scalar attributes.
Vectors: Displays different types of glyphs oriented and colored as per vector data at the input points. This is merely a convenience module that is entirely based on the Glyph module.
Volume: The Volume module visualizes scalar fields using volumetric visualization techniques.
WarpVectorCutPlane: Takes an arbitrary slice of the input data using an implicit cut plane and warps it according to the vector field data. The scalars are displayed on the warped surface as colors.

Mayavi2 Filters

CellDerivatives: Computes derivatives from input point scalar and vector data and produces cell data on the gradients. Can be used to approximately calcuate the vorticity for example.
CellToPointData: Transforms cell attribute data to point data by averaging the cell data from the cells at the point.
Contour: A contour filter that wraps around the Contour component to generate iso-surfaces on any input dataset.
CutPlane: This class represents a cut plane that can be used to slice through any dataset. It also provides a 3D widget interface to position and move the slice interactively.
ElevationFilter: Creates scalar data corresponding to the elevation of the points along a line.
Delaunay2D: Performs a 2D Delaunay triangulation.
Delaunay3D: Performs a 3D Delaunay triangulation.
ExtractEdges: This filter extracts cell edges from any input data.
ExtractGrid: Allows a user to select a part of a structured grid.
ExtractTensorComponents: Wraps the TVTK ExtractTensorComponents filter to extract components from a tensor field.
ExtractUnstructuredGrid: Allows a user to select a part of an unstructured grid.
ExtractVectorNorm: Computes the norm (Eucliedean) of the input vector data (with optional scaling between [0, 1]). This is useful when the input data has vector input but no scalar data for the magnitude of the vectors.
ExtractVectorComponents: Wraps the TVTK ExtractVectorComponents filter to extract components of a vector. This is useful for analysing individual components of a vector data.
GaussianSplatter: This filter splat points into a volume with an elliptical, Gaussian distribution.
MaskPoints: Selectively passes the input points downstream. This can be used to subsample the input points. Note that this does not pass geometry data, this means all grid information is lost.
GreedyTerrainDecimation: Approximates a height field (image data) with a triangle mesh, keeping the number of triangles minimum.
ImageChangeInformation: A filter that can be used to change the origin, spacing and extents of an input image dataset without changing the data itself.
ImageDataProbe: A filter that can be used to probe any dataset using a Structured Points dataset. The filter also allows one to convert the scalar data to an unsigned short array so that the scalars can be used for volume visualization.
PointToCellData: Does the inverse of the CellToPointData filter.
PolyDataNormals: Computes normals from input data. This gives meshes a smoother appearance. This should work for any input dataset. Note: this filter is called "Compute Normals" in Mayavi2 GUI (Visualize/Filters/Compute Normals).
QuadricDecimation: Reduce triangles in a mesh, forming a good approximation of the original mesh.
SelectOutput: A filter that allows a user to select one among several of the outputs of a given input. This is typically very useful for a multi-block data source.
SetActiveAttribute: This filter lets a user set the active data attribute (scalars, vectors and tensors) on a VTK dataset. This is particularly useful if you need to do something like compute contours of one scalar on the contour of another scalar.
Stripper: Create triangle strips and/or poly-lines. Useful for regularizing broken up surfaces, such as those created by the Tube filter. .
Threshold: A simple filter that thresholds on input data.
TransformData: Performs a linear transformation to input data.
TriangleFilter: Converts input polygons and triangle strips to triangles using the tvtk.TriangleFilter class. This is useful when you have a downstream filter that only processes triangles.
Tube: Turns lines into tubes.
UserDefined: This filter lets the user define their own filter dynamically/interactively. It is like FilterBase but allows a user to specify the class without writing any code.
Vorticity: This filter computes the vorticity of an input vector field. For convenience, the filter allows one to optionally pass-through the given input vector field. The filter also allows the user to show the component of the vorticity along a particular cartesian co-ordinate axes. It produces point data on output which is ready to visualize.
WarpScalar: Warps the input data along a particular direction (either the normals or a specified direction) with a scale specified by the local scalar value. Useful for making carpet plots.
WarpVector: Warps the input data along a the point vector attribute scaled as per a scale factor. Useful for showing flow profiles or displacements.

Examples

mayavi2 -d heart.vtk -m Axes -m Outline -m GridPlane -m ContourGridPlane -m IsoSurface
mayavi2 -d fire_ug.vtu -m Axes -m Outline -m VectorCutPlane -f MaskPoints -m Glyph

In the above examples, heart.vti and fire_ug.vtu VTK files can be found in /usr/share/doc/mayavi2/examples/data. The examples directory (/usr/share/doc/mayavi2/examples/ on Debian) provides several useful examples.

Author

Mayavi was originally developed by Prabhu Ramachandran. Many people have later contributed to it.

More information on Mayavi2 can be obtained from http://code.enthought.com/mayavi2