Create mesh from cells and points in Paraview

问题

I have a CSV file with stress data and geometry that I have exported from ANSYS Mechanical that I would like to visualize in Paraview. Each node has a bunch of stress data related to it. I managed import the points as a point cloud in Paraview but I want to recreate the ANSYS mesh as well. I thought that "programable source" in Paraview could be an alternative way and with some googleing I could probably figure out how to read the data in to numpy arrays but the fundamental question is, how can I create mesh in programable source in Paraview from points and cells/faces? My CSV file looks something like this:

Node, X, Y, Z, Stress_data
1, 1.0, 1.0, 1.0, 123
2, 2.0, 2.0, 2.0, 234
3, 3.0, 3.0, 3.0, 345
...

Faces
1, 2, 3
3, 4, 5
...

Update
Here is a link to an example csv file (connectivity column included), how the mesh looks in Ansys, how the mesh looks in Paraview and an slightly modified script.

回答1:

The following python script creates a polydata object from your csv-file and writes it to a file, that can be read in paraview:

import vtk

f = open('Example-2.csv')

pd = vtk.vtkPolyData()
points = vtk.vtkPoints()
cells = vtk.vtkCellArray()
connectivity = vtk.vtkIntArray()
connectivity.SetName('Connectivity')
stress = vtk.vtkFloatArray()
stress.SetName('Stress')

line = f.readline()
for line in iter(lambda: f.readline(), ""):
    if 'Faces' in line:
        break
    v = line.split(',')
    points.InsertNextPoint(float(v[1]),
                           float(v[2]),
                           float(v[3]))
    stress.InsertNextTuple1(float(v[5]))
    connectivity.InsertNextTuple1(float(v[4]))

for line in iter(lambda: f.readline(), ""):
    v = line.split(',')
    cell = vtk.vtkTriangle()
    Ids = cell.GetPointIds()
    for kId in range(len(v)):
        Ids.SetId(kId,int(v[kId]))
    cells.InsertNextCell(cell)
f.close()

pd.SetPoints(points)
pd.SetPolys(cells)
pd.GetPointData().AddArray(stress)
pd.GetPointData().AddArray(connectivity)

writer = vtk.vtkXMLPolyDataWriter()
writer.SetFileName('Example-2.vtp')
writer.SetInputData(pd)

writer.Write()

Or you could use a programmable filter on your csv-file (see here). This way I'm not sure how to feed node and face data into separate objects.

来源：https://stackoverflow.com/questions/45665130/create-mesh-from-cells-and-points-in-paraview

标签

python

csv

numpy

vtk

paraview