"""Postprocessing utils based on VTK library"""
import vtk
import os
import tempfile
vtk_version = vtk.vtkVersion().GetVTKMajorVersion()
[docs]def get_vtk_from_file(filename):
"""
Read VTK file.
Parameters
----------
filename : str
Name of the VTK file.
Returns
-------
vtkdata : VTK object
Mesh, scalar, vector and tensor data.
"""
reader = vtk.vtkUnstructuredGridReader()
reader.SetFileName(filename)
reader.ReadAllScalarsOn()
reader.ReadAllVectorsOn()
reader.ReadAllTensorsOn()
reader.Update()
return reader.GetOutput()
[docs]def write_vtk_to_file(filename, vtkdata):
"""
Write VTK file.
Parameters
----------
filename : str
Name of the VTK file.
vtkdata : VTK object
Mesh, scalar, vector and tensor data.
"""
writer = vtk.vtkGenericDataObjectWriter()
writer.SetFileName(filename)
if vtk_version < 6:
writer.SetInput(vtkdata)
else:
writer.SetInputData(vtkdata)
writer.Update()
[docs]def get_vtk_from_mesh(mesh, data, prefix=''):
mesh_name = mesh.name[mesh.name.rfind(os.path.sep) + 1:]
tmpdir = tempfile.gettempdir()
vtkname = os.path.join(tmpdir, '%s%s.vtk' % (prefix, mesh_name))
mesh.write(vtkname, io='auto', out=data)
vtkdata = get_vtk_from_file(vtkname)
os.remove(vtkname)
return vtkdata
[docs]def get_vtk_surface(vtkdata):
"""
Get mesh surface.
Parameters
----------
vtkdata : VTK object
Mesh, scalar, vector and tensor data.
Returns
-------
surface : VTK object
Mesh, scalar, vector and tensor data.
"""
surface = vtk.vtkDataSetSurfaceFilter()
if vtk_version < 6:
surface.SetInput(vtkdata)
else:
surface.SetInputData(vtkdata)
surface.Update()
return surface.GetOutput()
[docs]def get_vtk_edges(vtkdata):
"""
Get mesh edges.
Parameters
----------
vtkdata : VTK object
Mesh, scalar, vector and tensor data.
Returns
-------
edges : VTK object
Mesh, scalar, vector and tensor data.
"""
edges = vtk.vtkExtractEdges()
if vtk_version < 6:
edges.SetInput(vtkdata)
else:
edges.SetInputData(vtkdata)
edges.Update()
return edges.GetOutput()
[docs]def get_vtk_by_group(vtkdata, group_lower, group_upper=None):
"""
Get submesh by material group id.
Parameters
----------
vtkdata : VTK object
Mesh, scalar, vector and tensor data.
group_lower : int
The lower material id.
group_lower : int
The Upper material id.
Returns
-------
slection : VTK object
Mesh, scalar, vector and tensor data.
"""
selection = vtk.vtkThreshold()
if vtk_version < 6:
selection.SetInput(vtkdata)
else:
selection.SetInputData(vtkdata)
selection.SetInputArrayToProcess(0, 0, 0,
vtk.vtkDataObject.FIELD_ASSOCIATION_CELLS,
"mat_id")
if group_upper is None:
group_upper = group_lower
selection.ThresholdBetween(group_lower, group_upper)
selection.Update()
return selection.GetOutput()
[docs]def tetrahedralize_vtk_mesh(vtkdata):
"""
3D cells are converted to tetrahedral meshes, 2D cells to triangles.
Parameters
----------
vtkdata : VTK object
Mesh, scalar, vector and tensor data.
Returns
-------
tetra : VTK object
Mesh, scalar, vector and tensor data.
"""
tetra = vtk.vtkDataSetTriangleFilter()
if vtk_version < 6:
tetra.SetInput(vtkdata)
else:
tetra.SetInputData(vtkdata)
tetra.Update()
return tetra.GetOutput()