vtkIntegrateAttributes (possible error)

Support
1

I am trying to use the vtkIntegrateAttributes. According to the documentation the output should be divided by the area or volume if I use vtkIntegrateAttributes.SetDivideAllCellDataByVolume but the result is unchanged. I have verified that the barycentric integration is correct, but it would be nice it could be normalized by the volume.

a small example demonstrating the issue

import vtk

rnd = vtk.vtkRandomPool()

vertexValues = vtk.vtkDoubleArray()
vertexValues.SetNumberOfComponents(1)
vertexValues.SetNumberOfTuples(3)
vertexValues.SetName("VertexData")
rnd.PopulateDataArray(vertexValues, 0.0, 1.0)

vertices = vtk.vtkDoubleArray()
vertices.SetNumberOfComponents(3)
vertices.SetNumberOfTuples(3)
rnd.PopulateDataArray(vertices, 0.0, 5.0)

points = vtk.vtkPoints()
points.InsertNextPoint(vertices.GetTuple3(0))
points.InsertNextPoint(vertices.GetTuple3(1))
points.InsertNextPoint(vertices.GetTuple3(2))

triangle = vtk.vtkTriangle()
triangle.GetPointIds().SetId(0, 0)
triangle.GetPointIds().SetId(1, 1)
triangle.GetPointIds().SetId(2, 2)

triangles = vtk.vtkCellArray()
triangles.InsertNextCell(triangle)

triangles = vtk.vtkCellArray()
triangles.InsertNextCell(triangle)

trianglePolyData = vtk.vtkPolyData()

trianglePolyData.SetPoints(points)
trianglePolyData.SetPolys(triangles)
trianglePolyData.GetPointData().AddArray(vertexValues)

integrator = vtk.vtkIntegrateAttributes()
integrator.SetInputData(trianglePolyData)
integrator.SetInputArrayToProcess(0,0,0,0, "VertexData")
integrator.Update()

integral = integrator.GetOutput().GetPointData()
intValues = integral.GetArray("VertexData")
print("integrated VertexData: %f" % (intValues.GetValue(0)))

integrator.SetDivideAllCellDataByVolume(1)
integrator.Update()
integral = integrator.GetOutput().GetPointData()
intValues = integral.GetArray("VertexData")
print("integrated VertexData: %f" % (intValues.GetValue(0)))

I can find the area using GetCellData, but integrated attribute is divided by the area / volume

2

Hello,

My two cents: maybe the normalized varlues are refered by a different array?

regards,

PC

3

Also my initial thought. I went through all the output arrays, both PointData and CellData, no normalized values are present. Will debug the filter and figure out what is going on. Looked into the filter since I needed to compute the variance of integrated attributes.