Found out about the vtkImplicitModeller, replaced the vtkCellDataToPontData with it and am satisfied with the result.
What I dislike though, is that the contoured polydata contains the isovalue as scalar value and not the isovalue the cells had before. I could change the isovalue of course, but the generated surface looks best with an isovalue of 1. Therefore I want to change the scalar values to a specified value, for example 16. Unfortunately GetNumberOfTuples() in the following code gives me a segmentation fault. What do I do wrong or is there another more efficient way to accomplish this?
vtkContourFilter* contour = vtkContourFilter::New();
contour->SetInputConnection(im->GetOutputPort());
contour->SetValue(0,1);
vtkPolyData* polyData = contour->GetOutput();
vtkCellData* cellData = polyData->GetCellData();
vtkDataArray* colors = cellData->GetScalars();
for(int i=0; i<colors->GetNumberOfTuples(); i++)
colors->SetComponent(i,0,16);
Thanks in advance
c674 wrote
What I am trying to do is put a surface over data in an unstructured grid, containing cubes with cell data. My code looks like this:
vtkUnstructuredGridReader* reader = vtkUnstructuredGridReader::New();
reader->SetFileName("test_input.vtk");
reader->Update();
vtkCellDataToPointData* conv = vtkCellDataToPointData::New();
conv->SetInput(reader->GetOutput());
vtkContourFilter* contour = vtkContourFilter::New();
contour->SetInput(conv->GetOutput());
contour->SetValue(0,1);
vtkPolyDataWriter* writer = vtkPolyDataWriter::New();
writer->SetFileName("test_output.vtk");
ostream *file= writer->OpenVTKFile();
writer->WriteHeader(file);
writer->SetInputConnection(contour->GetOutputPort());
writer->Write();
writer->CloseVTKFile(file);
Unfortunately my output file does not contain any data. The cell data is in the range from 0 to 40. Does this give a hint on how to chose my isovalue? I've played with that value a lot, without success.
When replacing the vtkCellDataToPointData with a vtkSurfaceReconstructionFilter I get output for isovalues between 1 and 3, I'm not satisfied with the look of the output though and I want it to work without that filter.
What is the role of the isovalue anyways? I thought it was no more than some kind of threshold, to decide which points are taken into account - but then isovalues between 0 and 40 should give output, shouldn't they?
Locked
