HighlightWithSilhouette
Repository source: HighlightWithSilhouette
Description¶
Click on a sphere to highlight it. vtkPolyDataSilhoutte creates a silhouette of the picked vtkActor. The example subclasses vtkInteractorStyleTrackballCamera with a local class called MouseInteractorHighLightActor. The new interactor overrides the OnLeftButtonDown of vtkInteractorStyleTrackballCamera.
Watch this video showing the picking of several spheres.
Seealso
HighlightPickedActor C++ or Python where the color and edge visibility of the picked actor is changed.
Other languages
See (Python), (PythonicAPI)
Question
If you have a question about this example, please use the VTK Discourse Forum
Code¶
HighlightWithSilhouette.cxx
#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkMinimalStandardRandomSequence.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkPolyDataSilhouette.h>
#include <vtkPropPicker.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSphereSource.h>
namespace {
// Handle mouse events
class MouseInteractorHighLightActor : public vtkInteractorStyleTrackballCamera
{
public:
static MouseInteractorHighLightActor* New();
vtkTypeMacro(MouseInteractorHighLightActor,
vtkInteractorStyleTrackballCamera);
MouseInteractorHighLightActor()
{
LastPickedActor = nullptr;
SilhouetteActor = nullptr;
Silhouette = nullptr;
}
virtual ~MouseInteractorHighLightActor()
{
}
virtual void OnLeftButtonDown() override
{
int* clickPos = this->GetInteractor()->GetEventPosition();
// Pick from this location.
vtkNew<vtkPropPicker> picker;
picker->Pick(clickPos[0], clickPos[1], 0, this->GetDefaultRenderer());
this->LastPickedActor = picker->GetActor();
// If we picked something before, remove the silhouette actor and
// generate a new one
if (this->LastPickedActor)
{
this->GetDefaultRenderer()->RemoveActor(this->SilhouetteActor);
// Highlight the picked actor by generating a silouhette
this->Silhouette->SetInputData(
dynamic_cast<vtkPolyDataMapper*>(this->LastPickedActor->GetMapper())
->GetInput());
this->GetDefaultRenderer()->AddActor(this->SilhouetteActor);
}
// Forward events
vtkInteractorStyleTrackballCamera::OnLeftButtonDown();
}
void SetSilhouette(vtkPolyDataSilhouette* silhouette)
{
this->Silhouette = silhouette;
}
void SetSilhouetteActor(vtkActor* silhouetteActor)
{
this->SilhouetteActor = silhouetteActor;
}
private:
vtkActor* LastPickedActor;
vtkActor* SilhouetteActor;
vtkPolyDataSilhouette* Silhouette;
};
vtkStandardNewMacro(MouseInteractorHighLightActor);
} // namespace
// Execute application.
int main(int argc, char* argv[])
{
vtkNew<vtkNamedColors> colors;
colors->SetColor("Bkg", 0.3, 0.4, 0.5);
int numberOfSpheres = 10;
if (argc > 1)
{
numberOfSpheres = atoi(argv[1]);
}
// Create a renderer and render window
vtkNew<vtkRenderer> renderer;
vtkNew<vtkRenderWindow> renderWindow;
renderWindow->SetSize(640, 480);
renderWindow->AddRenderer(renderer);
renderWindow->SetWindowName("HighlightWithSilhouette");
// An interactor
vtkNew<vtkRenderWindowInteractor> interactor;
interactor->SetRenderWindow(renderWindow);
vtkNew<vtkMinimalStandardRandomSequence> randomSequence;
randomSequence->SetSeed(8775070);
for (int i = 0; i < numberOfSpheres; ++i)
{
vtkNew<vtkSphereSource> source;
double x, y, z, radius;
// random position and radius
x = randomSequence->GetRangeValue(-5.0, 5.0);
randomSequence->Next();
y = randomSequence->GetRangeValue(-5.0, 5.0);
randomSequence->Next();
z = randomSequence->GetRangeValue(-5.0, 5.0);
randomSequence->Next();
radius = randomSequence->GetRangeValue(0.5, 1.0);
randomSequence->Next();
source->SetRadius(radius);
source->SetCenter(x, y, z);
source->SetPhiResolution(11);
source->SetThetaResolution(21);
vtkNew<vtkPolyDataMapper> mapper;
mapper->SetInputConnection(source->GetOutputPort());
vtkNew<vtkActor> actor;
actor->SetMapper(mapper);
double r, g, b;
r = randomSequence->GetRangeValue(0.4, 1.0);
randomSequence->Next();
g = randomSequence->GetRangeValue(0.4, 1.0);
randomSequence->Next();
b = randomSequence->GetRangeValue(0.4, 1.0);
randomSequence->Next();
actor->GetProperty()->SetDiffuseColor(r, g, b);
actor->GetProperty()->SetDiffuse(0.8);
actor->GetProperty()->SetSpecular(0.5);
actor->GetProperty()->SetSpecularColor(
colors->GetColor3d("White").GetData());
actor->GetProperty()->SetSpecularPower(30.0);
renderer->AddActor(actor);
}
renderer->SetBackground(colors->GetColor3d("SteelBlue").GetData());
// Render and interact
renderWindow->Render();
// Create the silhouette pipeline, the input data will be set in the
// interactor
vtkNew<vtkPolyDataSilhouette> silhouette;
silhouette->SetCamera(renderer->GetActiveCamera());
// Create mapper and actor for silhouette
vtkNew<vtkPolyDataMapper> silhouetteMapper;
silhouetteMapper->SetInputConnection(silhouette->GetOutputPort());
vtkNew<vtkActor> silhouetteActor;
silhouetteActor->SetMapper(silhouetteMapper);
silhouetteActor->GetProperty()->SetColor(
colors->GetColor3d("Tomato").GetData());
silhouetteActor->GetProperty()->SetLineWidth(5);
// Set the custom type to use for interaction.
vtkNew<MouseInteractorHighLightActor> style;
style->SetDefaultRenderer(renderer);
style->SetSilhouetteActor(silhouetteActor);
style->SetSilhouette(silhouette);
interactor->SetInteractorStyle(style);
interactor->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
project(HighlightWithSilhouette)
find_package(VTK COMPONENTS
CommonColor
CommonCore
FiltersHybrid
FiltersSources
InteractionStyle
RenderingContextOpenGL2
RenderingCore
RenderingFreeType
RenderingGL2PSOpenGL2
RenderingOpenGL2
)
if (NOT VTK_FOUND)
message(FATAL_ERROR "HighlightWithSilhouette: 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(HighlightWithSilhouette MACOSX_BUNDLE HighlightWithSilhouette.cxx )
target_link_libraries(HighlightWithSilhouette PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS HighlightWithSilhouette
MODULES ${VTK_LIBRARIES}
)
Download and Build HighlightWithSilhouette¶
Click here to download HighlightWithSilhouette and its CMakeLists.txt file. Once the tarball HighlightWithSilhouette.tar has been downloaded and extracted,
cd HighlightWithSilhouette/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:
./HighlightWithSilhouette
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.