# Can I generate a representation of the cell tree locator?

**URL:** https://discourse.vtk.org/t/can-i-generate-a-representation-of-the-cell-tree-locator/13319
**Category:** Development
**Created:** [February 14, 2024, 11:41pm UTC](https://discourse.vtk.org/t/can-i-generate-a-representation-of-the-cell-tree-locator/13319 "2024-02-14T23:41:32Z")
**Posts on this page:** 4
**Page:** 1

<div class="post-metadata">

### Author: ![Rafael\_Scatena](https://discourse.vtk.org/user_avatar/discourse.vtk.org/rafael_scatena/32/7820_2.png) [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)
#### Post date: [February 14, 2024, 11:41pm UTC](https://discourse.vtk.org/t/can-i-generate-a-representation-of-the-cell-tree-locator/13319/1 "2024-02-14T23:41:32Z")

</div>

Hello,

I don’t know the answer since the celltreelocator does not have levels but buckets.  
Also I am rendering offscreen but it is working.

Thank you,

NAMESPACE:

```
namespace {class vtkSliderCallback : public vtkCommand
			{
			public:
			  static vtkSliderCallback* New()
			  { return new vtkSliderCallback;}

		  vtkSliderCallback() : Cell_Locator(0), Level(12), PolyData(0), Renderer(0) {}

		  virtual void Execute(vtkObject* caller, unsigned long, void*)
		  { vtkSliderWidget* sliderWidget = reinterpret_cast<vtkSliderWidget*>(caller);
this->Level = vtkMath::Round(static_cast<vtkSliderRepresentation*>(sliderWidget->GetRepresentation())->GetValue());
		    this->Cell_Locator->GenerateRepresentation(this->Level, this->PolyData);
		    this->Renderer->Render();}
	          
		  vtkCellTreeLocator* Cell_Locator;
		  int Level;
		  vtkPolyData* PolyData;
		  vtkRenderer* Renderer;};}

```

MAIN CODE:

```
            vtkNew<vtkCellTreeLocator> cell_locator_2;
			cell_locator_2->SetDataSet(polydata);
			cell_locator_2->SetNumberOfBuckets(max_level);
			cell_locator_2->SetNumberOfCellsPerNode(cells_perbuckets);
			cell_locator_2->CacheCellBoundsOn();
			cell_locator_2->BuildLocator();	
			
			cell_locator_2->GenerateRepresentation(0, polydata);
			
			datastructuretype = "Tree Cell Locator";

			// Calculate the elapsed time

			
			buildtime = datastructuretype +"Build Time: ";	

			
			datastructuretype = "Tree Cell Locator";

			// Calculate the elapsed time

			
			buildtime = datastructuretype +"Build Time: ";		

	
    
    

  			     	
			
 cell_locator_2->GenerateRepresentation(0, polydata); 
	

		  
		 std::cout << "Cell Locator: Num Levels: " << cell_locator_2->GetLevel() << " Per Leave: " << cell_locator_2->GetNumberOfBuckets()<<std::endl;	

		  vtkNew<vtkNamedColors> colors3;
		  vtkNew<vtkPolyDataMapper> pointsMapper;
		  pointsMapper->SetInputData(polydata);
  		          pointsMapper->ScalarVisibilityOff();
		  
		  vtkNew<vtkActor> pointsActor;
		  pointsActor->SetMapper(pointsMapper);
		  pointsActor->GetProperty()->SetInterpolationToFlat();
		  pointsActor->GetProperty()->SetColor(colors3->GetColor4d("Lime").GetData());
		  pointsActor->GetProperty()->SetOpacity(.2);

		  pointsActor->RotateWXYZ(-90.0, 1.0, 0.0, 0.0);
		  pointsActor->Modified();
		  
		  // Initialize the representation.

		  vtkNew<vtkPolyDataMapper> locatorTreeMapper;
		  locatorTreeMapper->SetInputData(polydata);

		  vtkNew<vtkActor> locatorTreeActor;
		  locatorTreeActor->SetMapper(locatorTreeMapper);
		  locatorTreeActor->GetProperty()->SetOpacity(.5);
		  locatorTreeActor->GetProperty()->EdgeVisibilityOn();
		  locatorTreeActor->GetProperty()->SetColor(colors3->GetColor4d("Green").GetData());
		  locatorTreeActor->GetProperty()->SetInterpolationToFlat();
		  locatorTreeActor->GetProperty()->SetRepresentationToWireframe();
		  locatorTreeActor->RotateWXYZ(-90.0, 1.0, 0.0, 0.0);
		  locatorTreeActor->Modified();

		  // A renderer and render window.
		  vtkNew<vtkRenderer> renderer;
		  vtkNew<vtkEGLRenderWindow> renderWindow;			  
		  renderWindow->AddRenderer(renderer);
		   
	/* vtkNew<vtkNamedColors> colors2;
		  vtkNew<vtkTextActor> txt;
		  txt->SetInput(buildtime.c_str());
		  vtkTextProperty* txtprop = txt->GetTextProperty();
		  txtprop->SetFontFamilyToArial();
		  txtprop->SetFontSize(15);
		  txtprop->SetColor(colors2->GetColor4d("Blue").GetData());
		  txt->SetDisplayPosition(20, 12);*/
	
		   // An interactor.
		  vtkNew<vtkInteractorStyleTrackballCamera> style;
		  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
		  renderWindowInteractor->SetRenderWindow(renderWindow);
		  renderWindowInteractor->SetInteractorStyle(style);

		  // Add the actors to the scene.
		  renderer->AddActor(pointsActor);
		  renderer->AddActor(locatorTreeActor);
		  renderer->SetBackground(colors3->GetColor3d("Teal").GetData());
	// renderer->AddActor(txt);
		  renderer->UseHiddenLineRemovalOn();
		  renderer->Modified();
		  

		  renderWindow->OffScreenRenderingOn();
		  renderWindow->SetShowWindow(false);
		//renderWindow->WindowInitialize();
		  renderWindow->SetSize(640, 480);
		  renderWindow->SetWindowName("CellLocatorVisualization");
		  renderWindow->Render();

		   vtkNew<vtkSliderRepresentation2D> sliderRep;
		   sliderRep->SetMinimumValue(0);
		   sliderRep->SetMaximumValue(cell_locator_2->GetNumberOfBuckets());
		   sliderRep->SetValue(cell_locator_2->GetNumberOfBuckets());;

		//sliderRep->SetTitleText("MaxPointsPerRegion");
		  sliderRep->GetPoint1Coordinate()->SetCoordinateSystemToNormalizedDisplay();
		  sliderRep->GetPoint1Coordinate()->SetValue(.2, .1);
		  sliderRep->GetPoint2Coordinate()->SetCoordinateSystemToNormalizedDisplay();
		  sliderRep->GetPoint2Coordinate()->SetValue(.8, .1);
		  sliderRep->SetSliderLength(0.075);
		  sliderRep->SetSliderWidth(0.05);
		  sliderRep->SetEndCapLength(0.05);
		  sliderRep->GetTitleProperty()->SetColor(colors3->GetColor3d("Beige").GetData());
		  sliderRep->GetCapProperty()->SetColor(colors3->GetColor3d("MistyRose").GetData());
		  sliderRep->GetSliderProperty()->SetColor(colors3->GetColor3d("LightBlue").GetData());
		  sliderRep->GetSelectedProperty()->SetColor(colors3->GetColor3d("Violet").GetData());

		  vtkNew<vtkSliderWidget> sliderWidget;
		  sliderWidget->SetInteractor(renderWindowInteractor);
		  sliderWidget->SetRepresentation(sliderRep);
		  sliderWidget->SetAnimationModeToAnimate();
		  sliderWidget->EnabledOn();

		  vtkNew<vtkSliderCallback> callback;
          callback->Cell_Locator = cell_locator_2; break;
		  
		  callback->PolyData = polydata;
		  callback->Renderer = renderer;
		  callback->Execute(sliderWidget,0 , 0);

		  sliderWidget->AddObserver(vtkCommand::InteractionEvent, callback);
		  
		  
		  renderWindowInteractor->Initialize();
     	  renderWindow->Render();
		  renderWindowInteractor->Start();

		  vtkNew<vtkWindowToImageFilter> windowToImageFilter;
		  windowToImageFilter->SetInput(renderWindow);
		  windowToImageFilter->Update();
		    
		  
		  vtkNew<vtkPNGWriter> writer;
		  writer->SetFileName(datastructuretype.c_str());
		  writer->SetInputConnection(windowToImageFilter->GetOutputPort());
		  writer->Write();

```

 ![image](https://discourse.vtk.org/uploads/default/original/2X/0/0f7921f279bf968ae452f24f581118040ed8a6ee.jpeg)

---

<div class="post-metadata">

### Author: ![Paulo\_Carvalho](https://discourse.vtk.org/user_avatar/discourse.vtk.org/paulo_carvalho/32/370_2.png) [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)
#### Post date: [February 15, 2024, 5:58pm UTC](https://discourse.vtk.org/t/can-i-generate-a-representation-of-the-cell-tree-locator/13319/2 "2024-02-15T17:58:31Z")

</div>

Hello,

> [@Rafael\_Scatena](#):
>
> ```auto
> cell_locator_2->SetDataSet(polydata);
> (...)
> cell_locator_2->GenerateRepresentation(0, polydata);
> 
> ```

This is definitely a bad idea.

I suggest using a separate object to store the visual representation of the spatial index.

best,

PC

---

<div class="post-metadata">

### Author: ![Rafael\_Scatena](https://discourse.vtk.org/user_avatar/discourse.vtk.org/rafael_scatena/32/7820_2.png) [@Rafael\_Scatena](https://discourse.vtk.org/u/Rafael_Scatena)
#### Post date: [February 17, 2024, 12:16am UTC](https://discourse.vtk.org/t/can-i-generate-a-representation-of-the-cell-tree-locator/13319/3 "2024-02-17T00:16:05Z")

</div>

Hello,

Your tip worked fine for the OBBTree, CellLocator, and ModifiedBPSTree.  
However, for the CellTreeLocator I still can’t get a representation. I made the changes from “levels” to “NumberOfBuckets” but it didn’t work.

CellLocator vs. CellTreeLocator:

 ![image](https://discourse.vtk.org/uploads/default/original/2X/7/73fbfddd7649a55ab70c2e6276fa95a92bfd94f5.jpeg)

---

<div class="post-metadata">

### Author: ![Paulo\_Carvalho](https://discourse.vtk.org/user_avatar/discourse.vtk.org/paulo_carvalho/32/370_2.png) [@Paulo\_Carvalho](https://discourse.vtk.org/u/Paulo_Carvalho)
#### Post date: [February 17, 2024, 3:09pm UTC](https://discourse.vtk.org/t/can-i-generate-a-representation-of-the-cell-tree-locator/13319/4 "2024-02-17T15:09:02Z")

</div>

Hi,

Please, try calling `cell_locator_2->ForceBuildLocator()` before `GenerateRepresentation()`.

regards,

PC