[vtkusers] Color the faces of vtkUnstructuredGridGeometryFilter

[Bill Lorensen]

This example colors the faces of polydata. It might be useful:
http://vtk.org/Wiki/VTK/Examples/Cxx/PolyData/ColorCells


On Thu, Jan 17, 2013 at 5:19 AM, Gishara Indeewarie <gish.777 at gmail.com> wrote:
> Hi all,
>
> I am creating a vtkUnstructuredGrid and extract its faces using
> vtkUnstructuredGridGeometryFilter.
> I want to add colors to each face of the resulting unstructured grid.
> Is there a way that we can assign scalar data to faces?
> I tried with getCellData method but it did not give any output.
> Below is my code:
>
> #include <vtkVersion.h>
> #include <vtkCellArray.h>
> #include <vtkPoints.h>
> #include <vtkHexahedron.h>
> #include <vtkUnstructuredGrid.h>
>
> #include <vtkSmartPointer.h>
> #include <vtkDataSetMapper.h>
> #include <vtkActor.h>
> #include <vtkRenderWindow.h>
> #include <vtkRenderer.h>
> #include <vtkRenderWindowInteractor.h>
> #include <vtkCellData.h>
> #include <vtkCell.h>
> #include <vtkLookupTable.h>
> #include <vtkFloatArray.h>
> #include <vtkUnstructuredGridGeometryFilter.h>
> #include <vtkPointData.h>
>
> int main(int, char *[])
> {
>   // Setup the coordinates of eight points
>   // (the two faces must be in counter clockwise order as viewd from the
> outside)
>   double P0[3] = {0.0, 0.0, 0.0};
>   double P1[3] = {1.0, 0.0, 0.0};
>   double P2[3] = {1.0, 1.0, 0.0};
>   double P3[3] = {0.0, 1.0, 0.0};
>   double P4[3] = {0.0, 0.0, 1.0};
>   double P5[3] = {1.0, 0.0, 1.0};
>   double P6[3] = {1.0, 1.0, 1.0};
>   double P7[3] = {0.0, 1.0, 1.0};
>
>
>   // Create the points
>   vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
>   points->InsertNextPoint(P0);
>   points->InsertNextPoint(P1);
>   points->InsertNextPoint(P2);
>   points->InsertNextPoint(P3);
>   points->InsertNextPoint(P4);
>   points->InsertNextPoint(P5);
>   points->InsertNextPoint(P6);
>   points->InsertNextPoint(P7);
>
>   // Create a hexahedron from the points
>   vtkSmartPointer<vtkHexahedron> hex =
>     vtkSmartPointer<vtkHexahedron>::New();
>   hex->GetPointIds()->SetId(0,0);
>   hex->GetPointIds()->SetId(1,1);
>   hex->GetPointIds()->SetId(2,2);
>   hex->GetPointIds()->SetId(3,3);
>   hex->GetPointIds()->SetId(4,4);
>   hex->GetPointIds()->SetId(5,5);
>   hex->GetPointIds()->SetId(6,6);
>   hex->GetPointIds()->SetId(7,7);
>
>   // Add the hexahedron to a cell array
>   vtkSmartPointer<vtkCellArray> hexs =
>     vtkSmartPointer<vtkCellArray>::New();
>   hexs->InsertNextCell(hex);
>
>   vtkSmartPointer<vtkFloatArray> cellData =
>     vtkSmartPointer<vtkFloatArray>::New();
> for (int i = 0; i < 6; i++)
>     {
> cellData->InsertNextValue(i + 1);
>     }
>   // Add the points and hexahedron to an unstructured grid
>   vtkSmartPointer<vtkUnstructuredGrid> uGrid =
>     vtkSmartPointer<vtkUnstructuredGrid>::New();
>   uGrid->SetPoints(points);
>   uGrid->InsertNextCell(hex->GetCellType(), hex->GetPointIds());
>
>   vtkSmartPointer<vtkUnstructuredGridGeometryFilter> geometryFilter =
>     vtkSmartPointer<vtkUnstructuredGridGeometryFilter>::New();
>
>   geometryFilter->SetInput(uGrid);
>   geometryFilter->Update();
>
>   vtkUnstructuredGrid* grid2 = geometryFilter->GetOutput();
>  /grid2->GetCellData()->SetScalars(cellData);
>   // Create a lookup table to map cell data to colors
>   grid2->se
>   vtkSmartPointer<vtkLookupTable> lut =
>     vtkSmartPointer<vtkLookupTable>::New();
>   int tableSize = 1;
>   lut->SetNumberOfTableValues(tableSize);
>   lut->Build();
>
>
>   // Visualize
>   vtkSmartPointer<vtkDataSetMapper> mapper =
>     vtkSmartPointer<vtkDataSetMapper>::New();
> #if VTK_MAJOR_VERSION <= 5
>   mapper->SetInputConnection(grid2->GetProducerPort());
> #else
>   mapper->SetInputData(uGrid);
> #endif
>    mapper->SetScalarRange(0, tableSize - 1);
>   mapper->SetLookupTable(lut);
>
>   vtkSmartPointer<vtkActor> actor =
>     vtkSmartPointer<vtkActor>::New();
>   actor->SetMapper(mapper);
>
>   vtkSmartPointer<vtkRenderer> renderer =
>     vtkSmartPointer<vtkRenderer>::New();
>   vtkSmartPointer<vtkRenderWindow> renderWindow =
>     vtkSmartPointer<vtkRenderWindow>::New();
>   renderWindow->AddRenderer(renderer);
>   vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
>     vtkSmartPointer<vtkRenderWindowInteractor>::New();
>   renderWindowInteractor->SetRenderWindow(renderWindow);
>
>   renderer->AddActor(actor);
>   //renderer->SetBackground(.2, .3, .4);
>
>   renderWindow->Render();
>   renderWindowInteractor->Start();
>
>   return EXIT_SUCCESS;
> }
>
> Thanks in advance.
>
> _______________________________________________
> Powered by www.kitware.com
>
> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
>
> Please keep messages on-topic and check the VTK FAQ at:
> http://www.vtk.org/Wiki/VTK_FAQ
>
> Follow this link to subscribe/unsubscribe:
> http://www.vtk.org/mailman/listinfo/vtkusers
>



-- 
Unpaid intern in BillsBasement at noware dot com