[vtkusers] Picking and dragging a vertex - points not moving to appropriate position

[Dominik Szczerba]

Sounds very much like you miss dataset->Modified() somewhere.

Dominik

On Fri, Jun 17, 2011 at 10:41 AM, Vashist Purbhoo <vashist14 at hotmail.com> wrote:
> Hi vtkusers!
>
> I am trying to deform a 3D object by clicking and dragging its vertices.  I
> was able to adapt the "SelectAVertex.cxx" example
> (http://www.vtk.org/Wiki/VTK/Examples/Cxx/Interaction/MoveAVertex) on the
> vtk website to make it work with a polydata I create using vtkSphereSource.
> To summarise, to deform the object I select a vertex by clicking on the
> middle mouse button and drag the point to the new location I want.  I render
> the vertices of my object using
> vtkVertexGlyphFilter as well as the surface of the object.
>
> The program works correctly if I select the points without changing the
> initial view of the rendered object.  However, once I change the view, for
> example to access a point at the back of my object, the point no longer
> moves to where I drag it.  The coordinates returned do not correspond to the
> position where i release the mouse button.  I would highly appreciate if any
> help/suggestions could be provided on how to solve this.
>
> Thank you.
>
> Vashist
>
>
> #include <vtkSmartPointer.h>
> #include <vtkPointPicker.h>
> #include <vtkRendererCollection.h>
> #include <vtkProperty.h>
> #include <vtkObjectFactory.h>
> #include <vtkPolyDataMapper.h>
> #include <vtkActor.h>
> #include <vtkRenderWindow.h>
> #include <vtkRenderer.h>
> #include <vtkRenderWindowInteractor.h>
> #include <vtkPolyData.h>
> #include <vtkPointSource.h>
> #include <vtkInteractorStyleJoystickActor.h>
> #include <vtkAreaPicker.h>
> #include <vtkVertexGlyphFilter.h>
> #include <vtkIdFilter.h>
> #include <vtkAssembly.h>
> #include <vtkSphereSource.h>
> #include <vtkExtractGeometry.h>
> #include <vtkDataSetMapper.h>
> #include <vtkUnstructuredGrid.h>
> #include <vtkGlyph3D.h>
> #include <vtkPointData.h>
> #include <vtkIdTypeArray.h>
> #include <vtkDataSetSurfaceFilter.h>
> #include <vtkPlanes.h>
>
> class InteractorStyle : public vtkInteractorStyleJoystickActor
> {
>   public:
>     static InteractorStyle* New();
>     vtkTypeMacro(InteractorStyle,vtkInteractorStyleJoystickActor);
>
>     InteractorStyle()
>     {
>       this->Move = false;
>       this->PointPicker = vtkSmartPointer<vtkPointPicker>::New();
>
>       // Setup ghost glyph
>       vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
>       points->InsertNextPoint(0,0,0);
>       this->MovePolyData = vtkSmartPointer<vtkPolyData>::New();
>       this->MovePolyData->SetPoints(points);
>       this->MoveGlyphFilter = vtkSmartPointer<vtkVertexGlyphFilter>::New();
>
> this->MoveGlyphFilter->SetInputConnection(this->MovePolyData->GetProducerPort());
>       this->MoveGlyphFilter->Update();
>
>       this->MoveMapper = vtkSmartPointer<vtkPolyDataMapper>::New();
>
> this->MoveMapper->SetInputConnection(this->MoveGlyphFilter->GetOutputPort());
>
>       this->MoveActor = vtkSmartPointer<vtkActor>::New();
>       this->MoveActor->SetMapper(this->MoveMapper);
>       this->MoveActor->VisibilityOff();
>       this->MoveActor->GetProperty()->SetPointSize(5);
>       this->MoveActor->GetProperty()->SetColor(1,0,0);
>     }
>  //_____________________________________________________________________________________
>    void OnMouseMove()
>     {
>       if(!this->Move)
>         {
>         return;
>         }
>       vtkInteractorStyleJoystickActor::OnMouseMove();
>     }
>  //_____________________________________________________________________________________
>     void OnMiddleButtonUp()
>     {
>       this->EndPan();
>
>       this->Move = false;
>       this->MoveActor->VisibilityOff();
>       this->Data->GetPoints()->SetPoint(this->SelectedPoint,
> this->MoveActor->GetPosition());
>       this->Data->Modified();
>       this->GetCurrentRenderer()->Render();
>       this->GetCurrentRenderer()->GetRenderWindow()->Render();
>
>     }
> //_____________________________________________________________________________________
>     void OnMiddleButtonDown()
>     {
>       // Get the selected point
>       int x = this->Interactor->GetEventPosition()[0];
>       int y = this->Interactor->GetEventPosition()[1];
>       this->FindPokedRenderer(x, y);
>
>       this->PointPicker->Pick(this->Interactor->GetEventPosition()[0],
>                  this->Interactor->GetEventPosition()[1],
>                  0,  // always zero.
>
> this->Interactor->GetRenderWindow()->GetRenderers()->GetFirstRenderer());
>       if(this->PointPicker->GetPointId() >= 0)
>         {
>         this->StartPan();
>         this->MoveActor->VisibilityOn();
>         this->Move = true;
>         this->SelectedPoint = this->PointPicker->GetPointId();
>
>         std::cout << "Dragging point " << this->SelectedPoint << std::endl;
>
>         double p[3];
>         this->Data->GetPoint(this->SelectedPoint, p);
>         std::cout << "p: " << p[0] << " " << p[1] << " " << p[2] <<
> std::endl;
>         this->MoveActor->SetPosition(p);
>
>         this->GetCurrentRenderer()->AddActor(this->MoveActor);
>   this->InteractionProp = this->MoveActor;
>         }
>     }
>  //_____________________________________________________________________________________
>   vtkPolyData* Data;
>   vtkPolyData* GlyphData;
>
>   vtkSmartPointer<vtkPolyDataMapper> MoveMapper;
>   vtkSmartPointer<vtkActor> MoveActor;
>   vtkSmartPointer<vtkPolyData> MovePolyData;
>   vtkSmartPointer<vtkVertexGlyphFilter> MoveGlyphFilter;
>   vtkSmartPointer<vtkPointPicker> PointPicker;
>   bool Move;
>   vtkIdType SelectedPoint;
> };
> //_____________________________________________________________________________________
> vtkStandardNewMacro(InteractorStyle);
> //_____________________________________________________________________________________
>
> int main (int, char *[])
> {
>  // Create a sphere (object to be deformed)
>  vtkSmartPointer<vtkSphereSource> sphereSource =
> vtkSmartPointer<vtkSphereSource>::New();
>  sphereSource->SetCenter(20.0, 20.0, 20.0);
>  sphereSource->SetRadius(20.0);
>  sphereSource->SetThetaResolution(10);
>  sphereSource->SetPhiResolution(10);
>  sphereSource->Update();
>
>  //Create polydata from sphereSource
>  vtkSmartPointer<vtkPolyData> points_poly =
> vtkSmartPointer<vtkPolyData>::New();
>  points_poly->CopyStructure(sphereSource->GetOutput());
>
>  vtkSmartPointer<vtkVertexGlyphFilter> glyphFilter
> = vtkSmartPointer<vtkVertexGlyphFilter>::New();
>  glyphFilter->SetInputConnection(points_poly->GetProducerPort());
>  glyphFilter->Update();
>  // Create a mapper and actor
>  vtkSmartPointer<vtkPolyDataMapper> points_mapper =
> vtkSmartPointer<vtkPolyDataMapper>::New();
>  points_mapper->SetInputConnection(glyphFilter->GetOutputPort());
>
>  vtkSmartPointer<vtkActor> points_actor = vtkSmartPointer<vtkActor>::New();
>  points_actor->SetMapper(points_mapper);
>  points_actor->GetProperty()->SetPointSize(10);
>  vtkSmartPointer<vtkPolyDataMapper> Mapper2 =
> vtkSmartPointer<vtkPolyDataMapper>::New();
>  Mapper2->SetInput(points_poly);
>
>  vtkSmartPointer<vtkActor> Actor2 = vtkSmartPointer<vtkActor>::New();
>  Actor2->SetMapper(Mapper2);
>
>  //assembly to synchronise interaction of points & polydata
>  vtkSmartPointer<vtkAssembly> assembly
> = vtkSmartPointer<vtkAssembly>::New();
>  assembly->AddPart(points_actor);
>  assembly->AddPart(Actor2);
>  // Visualize
>  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(assembly);
>
>  renderWindow->Render();
>
>  vtkSmartPointer<InteractorStyle> style =
> vtkSmartPointer<InteractorStyle>::New();
>  renderWindowInteractor->SetInteractorStyle( style );
>  style->Data = points_poly;
>
>  renderWindowInteractor->Start();
>  return EXIT_SUCCESS;
> }
>
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