AffineWidget
VTKExamples/Cxx/Widgets/AffineWidget
Description¶
This example demonstrates use of a vtkAffineWidget to apply transforms to a 3D prop in the x-y plane.
Question
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Code¶
AffineWidget.cxx
#include <vtkActor.h> #include <vtkAffineRepresentation2D.h> #include <vtkAffineWidget.h> #include <vtkAppendPolyData.h> #include <vtkCommand.h> #include <vtkInteractorStyleSwitch.h> #include <vtkPlaneSource.h> #include <vtkPolyData.h> #include <vtkPolyDataMapper.h> #include <vtkProperty.h> #include <vtkRenderer.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkSmartPointer.h> #include <vtkSphereSource.h> #include <vtkTransform.h> class vtkAffineCallback : public vtkCommand { public: static vtkAffineCallback *New() { return new vtkAffineCallback; } virtual void Execute(vtkObject *caller, unsigned long, void*); vtkAffineCallback():Actor(0),AffineRep(0) { this->Transform = vtkTransform::New(); } ~vtkAffineCallback() { this->Transform->Delete(); } vtkActor *Actor; vtkAffineRepresentation2D *AffineRep; vtkTransform *Transform; }; void vtkAffineCallback::Execute(vtkObject*, unsigned long vtkNotUsed(event), void*) { this->AffineRep->GetTransform(this->Transform); this->Actor->SetUserTransform(this->Transform); } int main(int, char *[]) { // Create two spheres: a larger one and a smaller one on top of the larger one // to show a reference point while rotating vtkSmartPointer<vtkSphereSource> sphereSource = vtkSmartPointer<vtkSphereSource>::New(); sphereSource->Update(); vtkSmartPointer<vtkSphereSource> sphereSource2 = vtkSmartPointer<vtkSphereSource>::New(); sphereSource2->SetRadius(0.075); sphereSource2->SetCenter(0,0.5,0); sphereSource2->Update(); // Append the two spheres into one vtkPolyData vtkSmartPointer<vtkAppendPolyData> append = vtkSmartPointer<vtkAppendPolyData>::New(); append->AddInputConnection(sphereSource->GetOutputPort()); append->AddInputConnection(sphereSource2->GetOutputPort()); // Create a plane centered over the larger sphere with 4x4 sub sections vtkSmartPointer<vtkPlaneSource> planeSource = vtkSmartPointer<vtkPlaneSource>::New(); planeSource->SetXResolution(4); planeSource->SetYResolution(4); planeSource->SetOrigin(-1,-1,0); planeSource->SetPoint1(1,-1,0); planeSource->SetPoint2(-1,1,0); // Create a mapper and actor for the plane: show it as a wireframe vtkSmartPointer<vtkPolyDataMapper> planeMapper = vtkSmartPointer<vtkPolyDataMapper>::New(); planeMapper->SetInputConnection(planeSource->GetOutputPort()); vtkSmartPointer<vtkActor> planeActor = vtkSmartPointer<vtkActor>::New(); planeActor->SetMapper(planeMapper); planeActor->GetProperty()->SetRepresentationToWireframe(); planeActor->GetProperty()->SetColor(1,0,0); // Create a mapper and actor for the spheres vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New(); mapper->SetInputConnection(append->GetOutputPort()); vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New(); actor->SetMapper(mapper); // Create a renderer and render window vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New(); vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New(); renderWindow->AddRenderer(renderer); renderer->AddActor(actor); renderer->AddActor(planeActor); renderer->GradientBackgroundOn(); renderer->SetBackground(1,1,1); renderer->SetBackground2(0,0,1); // Create an interactor vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = vtkSmartPointer<vtkRenderWindowInteractor>::New(); renderWindowInteractor->SetRenderWindow(renderWindow); dynamic_cast<vtkInteractorStyleSwitch*>( renderWindowInteractor->GetInteractorStyle())->SetCurrentStyleToTrackballCamera(); // Create an affine widget to manipulate the actor // the widget currently only has a 2D representation and therefore applies transforms in the X-Y plane only vtkSmartPointer<vtkAffineWidget> affineWidget = vtkSmartPointer<vtkAffineWidget>::New(); affineWidget->SetInteractor(renderWindowInteractor); affineWidget->CreateDefaultRepresentation(); dynamic_cast<vtkAffineRepresentation2D*>(affineWidget->GetRepresentation())->PlaceWidget(actor->GetBounds()); vtkSmartPointer<vtkAffineCallback> affineCallback = vtkSmartPointer<vtkAffineCallback>::New(); affineCallback->Actor = actor; affineCallback->AffineRep = dynamic_cast<vtkAffineRepresentation2D*>(affineWidget->GetRepresentation()); affineWidget->AddObserver(vtkCommand::InteractionEvent,affineCallback); affineWidget->AddObserver(vtkCommand::EndInteractionEvent,affineCallback); renderWindow->Render(); renderWindowInteractor->Initialize(); renderWindow->Render(); affineWidget->On(); // begin mouse interaction renderWindowInteractor->Start(); return EXIT_SUCCESS; }
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.3 FATAL_ERROR) project(AffineWidget) find_package(VTK COMPONENTS vtkCommonCore vtkCommonDataModel vtkCommonTransforms vtkFiltersCore vtkFiltersSources vtkInteractionStyle vtkInteractionWidgets vtkRenderingContextOpenGL2 vtkRenderingCore vtkRenderingFreeType vtkRenderingGL2PSOpenGL2 vtkRenderingOpenGL2 QUIET) if (NOT VTK_FOUND) message("Skipping AffineWidget: ${VTK_NOT_FOUND_MESSAGE}") return () endif() message (STATUS "VTK_VERSION: ${VTK_VERSION}") if (VTK_VERSION VERSION_LESS "8.90.0") # old system include(${VTK_USE_FILE}) add_executable(AffineWidget MACOSX_BUNDLE AffineWidget.cxx ) target_link_libraries(AffineWidget PRIVATE ${VTK_LIBRARIES}) else () # include all components add_executable(AffineWidget MACOSX_BUNDLE AffineWidget.cxx ) target_link_libraries(AffineWidget PRIVATE ${VTK_LIBRARIES}) # vtk_module_autoinit is needed vtk_module_autoinit( TARGETS AffineWidget MODULES ${VTK_LIBRARIES} ) endif ()
Download and Build AffineWidget¶
Click here to download AffineWidget and its CMakeLists.txt file. Once the tarball AffineWidget.tar has been downloaded and extracted,
cd AffineWidget/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:
./AffineWidget
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.