PointLocatorVisualization
VTKExamples/Cxx/PolyData/PointLocatorVisualization
Description
The idea of this example is to navigate levels of a uniform spatial tree (vtkPointLocator) using a slider.
Note: it is not desirable to have PointsPerBucket set "too small". This is because at some point, refining a bucket will result in each cell in that bucket to also be in the bucket's children. This only wastes memory and computation. The value that is "too small" is dependent on the grid but in general a value between 10 and 100 should work well (the default value is 25).
Code
PointLocatorVisualization.cxx
#include <vtkVersion.h>
#include <vtkPointSource.h>
#include <vtkSphereSource.h>
#include <vtkPointLocator.h>
#include <vtkSmartPointer.h>
#include <vtkPolyData.h>
#include <vtkSliderWidget.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkPolyData.h>
#include <vtkSmartPointer.h>
#include <vtkCommand.h>
#include <vtkWidgetEvent.h>
#include <vtkCallbackCommand.h>
#include <vtkWidgetEventTranslator.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkSliderWidget.h>
#include <vtkSliderRepresentation2D.h>
#include <vtkProperty.h>
#include <vtkMath.h>
class vtkSliderCallback : public vtkCommand
{
public:
static vtkSliderCallback *New()
{
return new vtkSliderCallback;
}
vtkSliderCallback():PointLocator(0), Level(0), 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->PointLocator->GenerateRepresentation(this->Level, this->PolyData);
this->Renderer->Render();
}
vtkPointLocator* PointLocator;
int Level;
vtkPolyData* PolyData;
vtkRenderer* Renderer;
};
int main (int, char *[])
{
vtkSmartPointer<vtkSphereSource> inputSource =
vtkSmartPointer<vtkSphereSource>::New();
inputSource->SetPhiResolution(10);
inputSource->SetThetaResolution(10);
inputSource->Update();
vtkSmartPointer<vtkPolyDataMapper> pointsMapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
pointsMapper->SetInputConnection(inputSource->GetOutputPort());
vtkSmartPointer<vtkActor> pointsActor =
vtkSmartPointer<vtkActor>::New();
pointsActor->SetMapper(pointsMapper);
pointsActor->GetProperty()->SetInterpolationToFlat();
// Create the tree
vtkSmartPointer<vtkPointLocator> pointLocator =
vtkSmartPointer<vtkPointLocator>::New();
pointLocator->SetDataSet(inputSource->GetOutput());
pointLocator->BuildLocator();
// Initialize the representation
vtkSmartPointer<vtkPolyData> polydata =
vtkSmartPointer<vtkPolyData>::New();
pointLocator->GenerateRepresentation(0, polydata);
vtkSmartPointer<vtkPolyDataMapper> locatorTreeMapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
#if VTK_MAJOR_VERSION <= 5
locatorTreeMapper->SetInputConnection(polydata->GetProducerPort());
#else
locatorTreeMapper->SetInputData(polydata);
#endif
vtkSmartPointer<vtkActor> locatorTreeActor =
vtkSmartPointer<vtkActor>::New();
locatorTreeActor->SetMapper(locatorTreeMapper);
locatorTreeActor->GetProperty()->SetInterpolationToFlat();
locatorTreeActor->GetProperty()->SetRepresentationToWireframe();
// A renderer and render window
vtkSmartPointer<vtkRenderer> renderer =
vtkSmartPointer<vtkRenderer>::New();
vtkSmartPointer<vtkRenderWindow> renderWindow =
vtkSmartPointer<vtkRenderWindow>::New();
renderWindow->AddRenderer(renderer);
// An interactor
vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
renderWindowInteractor->SetRenderWindow(renderWindow);
// Add the actors to the scene
renderer->AddActor(pointsActor);
renderer->AddActor(locatorTreeActor);
// Render an image (lights and cameras are created automatically)
renderWindow->Render();
vtkSmartPointer<vtkSliderRepresentation2D> sliderRep =
vtkSmartPointer<vtkSliderRepresentation2D>::New();
sliderRep->SetMinimumValue(0);
sliderRep->SetMaximumValue(pointLocator->GetLevel());
sliderRep->SetValue(0);
sliderRep->SetTitleText("MaxPointsPerRegion");
sliderRep->GetPoint1Coordinate()->SetCoordinateSystemToNormalizedDisplay();
sliderRep->GetPoint1Coordinate()->SetValue(.2, .2);
sliderRep->GetPoint2Coordinate()->SetCoordinateSystemToNormalizedDisplay();
sliderRep->GetPoint2Coordinate()->SetValue(.8, .2);
sliderRep->SetSliderLength(0.075);
sliderRep->SetSliderWidth(0.05);
sliderRep->SetEndCapLength(0.05);
vtkSmartPointer<vtkSliderWidget> sliderWidget =
vtkSmartPointer<vtkSliderWidget>::New();
sliderWidget->SetInteractor(renderWindowInteractor);
sliderWidget->SetRepresentation(sliderRep);
sliderWidget->SetAnimationModeToAnimate();
sliderWidget->EnabledOn();
vtkSmartPointer<vtkSliderCallback> callback =
vtkSmartPointer<vtkSliderCallback>::New();
callback->PointLocator = pointLocator;
callback->PolyData = polydata;
callback->Renderer = renderer;
sliderWidget->AddObserver(vtkCommand::InteractionEvent,callback);
renderWindowInteractor->Initialize();
renderWindow->Render();
renderWindowInteractor->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(PointLocatorVisualization)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(PointLocatorVisualization MACOSX_BUNDLE PointLocatorVisualization.cxx)
target_link_libraries(PointLocatorVisualization ${VTK_LIBRARIES})
Download and Build PointLocatorVisualization
Click here to download PointLocatorVisualization and its CMakeLists.txt file. Once the tarball PointLocatorVisualization.tar has been downloaded and extracted,
cd PointLocatorVisualization/build
If VTK is installed:
cmake ..
If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:
cmake -DVTK_DIR:PATH=/home/me/vtk_build ..
Build the project:
make
and run it:
./PointLocatorVisualization
WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.