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.
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);
vtkInteractorStyleSwitch::SafeDownCast(
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();
vtkAffineRepresentation2D::SafeDownCast(affineWidget->GetRepresentation())->PlaceWidget(actor->GetBounds());
vtkSmartPointer<vtkAffineCallback> affineCallback =
vtkSmartPointer<vtkAffineCallback>::New();
affineCallback->Actor = actor;
affineCallback->AffineRep = vtkAffineRepresentation2D::SafeDownCast(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 2.8)
PROJECT(AffineWidget)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(AffineWidget MACOSX_BUNDLE AffineWidget.cxx)
target_link_libraries(AffineWidget ${VTK_LIBRARIES})
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 PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.