[vtkusers] vtkPointPicker Class

[Amy Squillacote]

Please keep the discussion on the vtkusers list rather than emailing me
directly. That way the discussion is archived and other people can
contribute to finding a solution to your problem..

The online documentation for vtkPointPicker is here:
http://www.vtk.org/doc/nightly/html/classvtkPointPicker.html.

- Amy

张涛 wrote:
> When I add a vtkPointPicker object to my program,I can't see any
> difference.I don't know how the vtkPointPicker class should perform
> and what its function exactly is. Can you do me a favor to send me an
> example of this class?
>
> 2007/5/14, Amy Squillacote <amy.squillacote at kitware.com
> <mailto:amy.squillacote at kitware.com>>:
>
>     Please be more specific than saying "it doesn't work". What doesn't
>     work? What behavior do you see, and what behavior do you expect?
>
>     - Amy
>
>     张涛 wrote:
>     > Hello
>     > I want to use the class vtkPointPicker to pick a point in a
>     > pointcloud,but it doesn't work
>     > Bellow is the snippet of my program,Please tell me what's the
>     problem.
>     >
>     > #include "vtkActor.h"
>     > #include "vtkPolyData.h"
>     > #include "vtkUnstructuredGrid.h"
>     > #include "vtkRenderWindow.h"
>     > #include "vtkRenderer.h "
>     > #include "vtkPointPicker.h "
>     > #include "vtkRenderWindowInteractor.h"
>     > #include "vtkPolyDataMapper.h"
>     > #include "vtkSphereSource.h"
>     > #include " vtkPolyDataReader.h"
>     > #include "vtkPolyDataMapper.h "
>     > #include "vtkShrinkFilter.h"
>     > #include "vtkDataSetMapper.h"
>     > #include "vtkRenderWindowInteractor.h "
>     > #include "vtkIdList.h"
>     >
>     > static void PickCells(void *);
>     > static vtkActor *sphereActor;
>     > static vtkPolyData *plateOutput;
>     > static vtkUnstructuredGrid *cells;
>     > static vtkRenderWindow *renWin;
>     > static vtkActor *cellsActor, *plateActor;
>     >
>     > //#include "SaveImage.h"
>     >
>     > int main( int argc, char *argv[] )
>     > {
>     > vtkRenderer *renderer = vtkRenderer::New();
>     > renWin = vtkRenderWindow::New();
>     > renWin->AddRenderer(renderer);
>     >
>     > vtkPointPicker *picker = vtkPointPicker::New();
>     > picker->SetTolerance(0.01);
>     >
>     > vtkRenderWindowInteractor *iren = vtkRenderWindowInteractor::New();
>     > iren->SetRenderWindow(renWin);
>     > iren->SetPicker(picker);
>     >
>     > // read data file
>     > // vtkPolyDataReader *plate = vtkPolyDataReader::New();
>     > // plate->SetFileName("../../../vtkdata/plate.vtk");
>     > //plate->DebugOn();
>     > int t,s;
>     > s = 0;
>     > FILE *fpread;
>     > float point[3];
>     > fpread = fopen("Inspection_Three.dat","r");
>     > vtkPolyData *PolyData = vtkPolyData::New();
>     > vtkPoints *pointsData = vtkPoints::New();
>     > vtkCellArray *PointsArray = vtkCellArray::New();
>     > while(!feof(fpread))
>     > {
>     > for(t = 0;t < 3;t++)
>     > {
>     > fscanf(fpread,"%f",&point[t]);
>     > }
>     > pointsData->InsertPoint(s,point[0],point[1],point[2]);
>     >
>     > PointsArray->InsertNextCell(1);
>     > PointsArray->InsertCellPoint(s);
>     >
>     > s++;
>     > }
>     >
>     > fclose(fpread);
>     > // PolyData->SetPoints(pointsData);
>     > // PolyData->SetVerts(PointsArray);
>     > // plateOutput = plate->GetOutput();
>     > plateOutput = vtkPolyData::New();
>     > plateOutput->SetPoints(pointsData);
>     > plateOutput->SetVerts(PointsArray);
>     > vtkPolyDataMapper *plateMapper = vtkPolyDataMapper::New();
>     > plateMapper->SetInput(plateOutput);
>     > plateActor = vtkActor::New();
>     > plateActor->SetMapper(plateMapper);
>     > plateActor->GetProperty()->SetColor(0.5000,0.5400,0.5300);
>     >
>     > // create marker for pick
>     > vtkSphereSource *sphere = vtkSphereSource::New();
>     > sphere->SetThetaResolution(8); sphere->SetPhiResolution(8);
>     > sphere->SetRadius(0.01);
>     > vtkPolyDataMapper *sphereMapper = vtkPolyDataMapper::New();
>     > sphereMapper->SetInput(sphere->GetOutput());
>     > sphereActor = vtkActor::New();
>     > sphereActor->SetMapper(sphereMapper);
>     > sphereActor->GetProperty()->SetColor(1,0,0);
>     > sphereActor->PickableOff();
>     >
>     > // create actor and mapper to display picked cells
>     > cells = vtkUnstructuredGrid::New();
>     > vtkShrinkFilter *shrink = vtkShrinkFilter::New();
>     > shrink->SetInput(cells);
>     > shrink->SetShrinkFactor( 0.75);
>     > vtkDataSetMapper *cellsMapper = vtkDataSetMapper::New();
>     > cellsMapper->SetInput(shrink->GetOutput());
>     > cellsActor = vtkActor::New();
>     > cellsActor->SetMapper(cellsMapper);
>     > cellsActor->PickableOff();
>     > cellsActor->VisibilityOff();
>     > cellsActor->GetProperty()->SetColor( 0.5000,0.5400,0.5300);
>     >
>     > renderer->AddActor(cellsActor);
>     > renderer->AddActor(plateActor);
>     > // renderer->AddActor(sphereActor);
>     > renderer->SetBackground(1,1,1);
>     > renderer->GetActiveCamera()->Elevation( 30.0);
>     > renderer->GetActiveCamera()->Azimuth(30.0);
>     > renderer->GetActiveCamera()->Zoom(0.75);
>     >
>     > renWin->SetSize(300,300);
>     >
>     > // interact with data
>     > renWin->Render();
>     >
>     > // SAVEIMAGE( renWin );
>     >
>     > iren->SetEndPickMethod(PickCells,(void *)iren);
>     > iren->Start();
>     >
>     > // Clean up
>     > renderer->Delete();
>     > renWin->Delete();
>     > picker->Delete();
>     > iren->Delete();
>     > // plate->Delete();
>     > plateMapper->Delete();
>     > plateActor->Delete();
>     > sphere->Delete();
>     > sphereMapper->Delete();
>     > sphereActor->Delete();
>     > cells->Delete();
>     > shrink->Delete();
>     > cellsMapper->Delete();
>     > cellsActor->Delete();
>     > }
>     >
>     > static void PickCells(void *arg)
>     > {
>     > vtkRenderWindowInteractor *iren = (vtkRenderWindowInteractor *)arg;
>     > vtkPointPicker *picker = (vtkPointPicker *)iren->GetPicker();
>     > int i, cellId;
>     > vtkIdList *cellIds = vtkIdList::New(); cellIds->Allocate(12);
>     > vtkIdList *ptIds = vtkIdList::New(); ptIds->Allocate(12);
>     >
>     > sphereActor->SetPosition(picker->GetPickPosition());
>     >
>     > if ( picker->GetPointId() >= 0 )
>     > {
>     > cout << "Point id: " << picker->GetPointId() << "\n";
>     > cellsActor->VisibilityOn();
>     > plateActor->VisibilityOff();
>     >
>     > cells->Initialize();
>     > cells->Allocate(100);
>     > cells->SetPoints(plateOutput->GetPoints());
>     >
>     > plateOutput->GetPointCells(picker->GetPointId(), cellIds);
>     > for (i=0; i < cellIds->GetNumberOfIds(); i++)
>     > {
>     > cellId = cellIds->GetId(i);
>     > plateOutput->GetCellPoints(cellId, ptIds);
>     > cells->InsertNextCell(plateOutput->GetCellType(cellId), ptIds);
>     > }
>     > }
>     > else
>     > {
>     > cellsActor->VisibilityOff();
>     > plateActor->VisibilityOn();
>     > }
>     >
>     > renWin->Render();
>     > cellIds->Delete();
>     > ptIds->Delete();
>     > }
>     >
>     >
>     >
>     >
>     >
>     ------------------------------------------------------------------------
>     >
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>     >
>
>     --
>     Amy Squillacote
>     Kitware, Inc.
>     28 Corporate Drive
>     Clifton Park, NY 12065
>     Phone: (518) 371-3971 x106
>
>

-- 
Amy Squillacote
Kitware, Inc.
28 Corporate Drive
Clifton Park, NY 12065
Phone: (518) 371-3971 x106