PointPicker
Repository source: PointPicker
Description¶
This example demonstrates how to get the closest point in the data set to the mouse click.
Question
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Code¶
PointPicker.cxx
#include <vtkActor.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPointPicker.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkRendererCollection.h>
#include <vtkSphereSource.h>
namespace {
// Define interaction style.
class MouseInteractorStylePP : public vtkInteractorStyleTrackballCamera
{
public:
static MouseInteractorStylePP* New();
vtkTypeMacro(MouseInteractorStylePP, vtkInteractorStyleTrackballCamera);
virtual void OnLeftButtonDown() override
{
std::cout << "Picking pixel: " << this->Interactor->GetEventPosition()[0]
<< " " << this->Interactor->GetEventPosition()[1] << std::endl;
this->Interactor->GetPicker()->Pick(this->Interactor->GetEventPosition()[0],
this->Interactor->GetEventPosition()[1],
0, // always zero.
this->Interactor->GetRenderWindow()
->GetRenderers()
->GetFirstRenderer());
double picked[3];
this->Interactor->GetPicker()->GetPickPosition(picked);
std::cout << "Picked value: " << picked[0] << " " << picked[1] << " "
<< picked[2] << std::endl;
// Forward events.
vtkInteractorStyleTrackballCamera::OnLeftButtonDown();
}
};
vtkStandardNewMacro(MouseInteractorStylePP);
} // namespace
int main(int, char*[])
{
vtkNew<vtkNamedColors> colors;
vtkNew<vtkSphereSource> sphereSource;
sphereSource->Update();
vtkNew<vtkPointPicker> pointPicker;
// Create a mapper and actor.
vtkNew<vtkPolyDataMapper> mapper;
mapper->SetInputConnection(sphereSource->GetOutputPort());
vtkNew<vtkActor> actor;
actor->SetMapper(mapper);
actor->GetProperty()->SetColor(colors->GetColor3d("MistyRose").GetData());
// Create a renderer, render window, and interactor.
vtkNew<vtkRenderer> renderer;
vtkNew<vtkRenderWindow> renderWindow;
renderWindow->AddRenderer(renderer);
renderWindow->SetWindowName("PointPicker");
vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
renderWindowInteractor->SetPicker(pointPicker);
renderWindowInteractor->SetRenderWindow(renderWindow);
vtkNew<MouseInteractorStylePP> style;
renderWindowInteractor->SetInteractorStyle(style);
// Add the actor to the scene.
renderer->AddActor(actor);
renderer->SetBackground(colors->GetColor3d("SlateGray").GetData());
// Render and interact.
renderWindow->Render();
renderWindowInteractor->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
project(PointPicker)
find_package(VTK COMPONENTS
CommonColor
CommonCore
FiltersSources
InteractionStyle
RenderingContextOpenGL2
RenderingCore
RenderingFreeType
RenderingGL2PSOpenGL2
RenderingOpenGL2
)
if (NOT VTK_FOUND)
message(FATAL_ERROR "PointPicker: Unable to find the VTK build folder.")
endif()
# Prevent a "command line is too long" failure in Windows.
set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
add_executable(PointPicker MACOSX_BUNDLE PointPicker.cxx )
target_link_libraries(PointPicker PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS PointPicker
MODULES ${VTK_LIBRARIES}
)
Download and Build PointPicker¶
Click here to download PointPicker and its CMakeLists.txt file. Once the tarball PointPicker.tar has been downloaded and extracted,
cd PointPicker/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:
./PointPicker
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.