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VTKBase.jl

The VTKBase.jl package contains common definitions used in the WriteVTK.jl and ReadVTK.jl packages.

VTK dataset types

VTKBase.VTKImageData — Type
VTKImageData <: StructuredVTKDataset

Represents the VTK image data format (.vti extension).

This corresponds to rectangular grids with uniform spacing in all directions.

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VTKBase.VTKRectilinearGrid — Type
VTKRectilinearGrid <: StructuredVTKDataset

Represents the VTK rectilinear grid format (.vtr extension).

This corresponds to rectangular grids with non-uniform spacing.

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VTKBase.VTKStructuredGrid — Type
VTKStructuredGrid <: StructuredVTKDataset

Represents the VTK structured grid format (.vts extension).

This corresponds to curvilinear grids, the most general kind of structured grid.

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VTKBase.VTKPolyData — Type
VTKPolyData <: UnstructuredVTKDataset

Represents the VTK polydata format (.vtp extension).

These are unstructured datasets that accept a limited set of cells types, defined in the PolyData module.

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VTKBase.VTKUnstructuredGrid — Type
VTKUnstructuredGrid <: UnstructuredVTKDataset

Represents the VTK unstructured format (.vtu extension).

This is the most general kind of unstructured grid, which accepts all cell types defined in the VTKCellTypes module.

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Field data types

In VTK, data can either be attached to the geometry (point and cell data), or not (field data).

VTKBase.VTKFieldData — Type
VTKFieldData <: AbstractFieldData

Represents data that is not attached to the grid geometry.

This is typically used for lightweight metadata, such as timestep information or strings.

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Cells in unstructured grids

General unstructured datasets

These are useful when working with general unstructured datasets (.vtu files).

VTKBase.VTKCellTypes.nodes — Function
nodes(c::VTKCellTypes)

Returns the number of nodes (or grid points) required by the cell type.

For instance, this returns 3 for VTK_TRIANGLE.

For cell types that can take any number of nodes, such as VTK_POLY_LINE, this returns -1.

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VTKBase.MeshCell — Type
MeshCell <: AbstractMeshCell

Single cell element in unstructured or polygonal grid.

It is characterised by a cell type (for instance, VTKCellType.TRIANGLE or PolyData.Strips) and by a connectivity vector determining the points on the grid defining this cell.

MeshCell(cell_type, connectivity)

Define a single cell element of an unstructured grid.

The cell_type argument characterises the type of cell (e.g. vertex, triangle, hexaedron, ...):

  • cell types for unstructured datasets are defined in the VTKCellTypes

module;

  • cell types for polygonal datasets are defined in the PolyData module.

The connectivity argument is a vector or tuple containing the indices of the points passed to vtk_grid which define this cell.

Example

Define a triangular cell passing by points with indices [3, 5, 42].

julia> cell = MeshCell(VTKCellTypes.VTK_TRIANGLE, (3, 5, 42))
MeshCell{VTKCellType, Tuple{Int64, Int64, Int64}}(VTKCellType("VTK_TRIANGLE", 0x05, 3), (3, 5, 42))
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Polygonal datasets

These are useful when working with polygonal datasets (.vtp files).

VTKBase.PolyData — Module
PolyData

Defines cell types for polygonal datasets.

The following singleton types are defined:

  • PolyData.Verts for vertices,
  • PolyData.Lines for lines,
  • PolyData.Strips for triangular strips,
  • PolyData.Polys for polygons.
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VTKBase.VTKPolyhedron — Type
VTKPolyhedron <: AbstractMeshCell

Represents a polyhedron cell in an unstructured grid.

Using VTKPolyhedron should be preferred to using a MeshCell with a cell type VTKCellTypes.VTK_POLYHEDRON, since the latter cannot hold all the necessary information to describe a polyhedron cell.

VTKPolyhedron(connectivity, faces...)

Construct polyhedron cell from connectivity vector (see MeshCell for details) and from a list of polyhedron faces.

Example

Create a polyhedron with 8 points and 6 faces. This can represent a cube if the 8 points are properly positioned.

julia> cell = VTKPolyhedron(
           1:8,
           (1, 4, 3, 2),
           (1, 5, 8, 4),
           (5, 6, 7, 8),
           (6, 2, 3, 7),
           (1, 2, 6, 5),
           (3, 4, 8, 7),
       )
VTKPolyhedron{UnitRange{Int64}, NTuple{6, NTuple{4, Int64}}}(1:8, ((1, 4, 3, 2), (1, 5, 8, 4), (5, 6, 7, 8), (6, 2, 3, 7), (1, 2, 6, 5), (3, 4, 8, 7)))
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Constants