.. _filters:
Filters
~~~~~~~
Filters transform the data, but do not display it. They are used as an
intermediate between the data sources and the modules.
Here is a list of the Mayavi Filters.
:CellDerivatives:
Computes derivatives from input point scalar and vector data
and produces cell data on the gradients. Can be used to
approximately calculate 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 filter 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.
:DataSetClipper:
This filter clips the dataset in an area. The area can be
defined interactively as a box, a sphere...
:DecimatePro:
Reduces the number of triangles in a triangular mesh by
approximating the original mesh.
:Delaunay2D:
Performs a 2D Delaunay triangulation.
:Delaunay3D:
Performs a 3D Delaunay triangulation.
:ElevationFilter:
Creates scalar data corresponding to the elevation of the
points along a line.
: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 (Euclidean) 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 analyzing
individual components of a vector data.
:GaussianSplatter:
This filter splat points into a volume with an elliptical,
Gaussian distribution. This is useful to estimate a density
field from a set of scattered points.
:GreedyTerrainDecimation:
Approximates a height field (2D 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 data 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.
: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.
:PointToCellData:
Does the inverse of the CellToPointData filter: converts data
located on the points to data located on the cells.
: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.
:Tube:
Turns lines into tubes.
:UserDefined:
This filter lets the user define their own filter
dynamically/interactively.
: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. The scalar value of a dataset can be, for
instance, converted in elevation.
:WarpVector:
Warps the input data along the point vector attribute
scaled as per a scale factor. Useful for showing flow
profiles or displacements.