IsoContours
VTKExamples/Cxx/ImplicitFunctions/IsoContours
Code
IsoContours.cxx
#include <vtkVersion.h>
#include <vtkSmartPointer.h>
#include <vtkInteractorStyleUser.h>
#include <vtkProperty.h>
#include <vtkOutlineFilter.h>
#include <vtkCommand.h>
#include <vtkSliderWidget.h>
#include <vtkSliderRepresentation.h>
#include <vtkSliderRepresentation3D.h>
#include <vtkImageData.h>
#include <vtkCellArray.h>
#include <vtkFloatArray.h>
#include <vtkPointData.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkContourFilter.h>
#include <vtkXMLImageDataWriter.h>
static void CreateData(vtkImageData* data);
class vtkSliderCallback : public vtkCommand
{
public:
static vtkSliderCallback *New()
{
return new vtkSliderCallback;
}
virtual void Execute(vtkObject *caller, unsigned long, void*)
{
vtkSliderWidget *sliderWidget =
reinterpret_cast<vtkSliderWidget*>(caller);
double value = static_cast<vtkSliderRepresentation *>(sliderWidget->GetRepresentation())->GetValue();
this->ContourFilter->GenerateValues(1, value, value);
}
vtkSliderCallback():ContourFilter(NULL) {}
vtkContourFilter* ContourFilter;
};
int main(int, char *[])
{
vtkSmartPointer<vtkImageData> data =
vtkSmartPointer<vtkImageData>::New();
CreateData(data);
// Create an isosurface
vtkSmartPointer<vtkContourFilter> contourFilter =
vtkSmartPointer<vtkContourFilter>::New();
#if VTK_MAJOR_VERSION <= 5
contourFilter->SetInput(data);
#else
contourFilter->SetInputData(data);
#endif
contourFilter->GenerateValues(1, 10, 10); // (numContours, rangeStart, rangeEnd)
// Map the contours to graphical primitives
vtkSmartPointer<vtkPolyDataMapper> contourMapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
contourMapper->SetInputConnection(contourFilter->GetOutputPort());
// Create an actor for the contours
vtkSmartPointer<vtkActor> contourActor =
vtkSmartPointer<vtkActor>::New();
contourActor->SetMapper(contourMapper);
// Create the outline
vtkSmartPointer<vtkOutlineFilter> outlineFilter =
vtkSmartPointer<vtkOutlineFilter>::New();
#if VTK_MAJOR_VERSION <= 5
outlineFilter->SetInput(data);
#else
outlineFilter->SetInputData(data);
#endif
vtkSmartPointer<vtkPolyDataMapper> outlineMapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
outlineMapper->SetInputConnection(outlineFilter->GetOutputPort());
vtkSmartPointer<vtkActor> outlineActor =
vtkSmartPointer<vtkActor>::New();
outlineActor->SetMapper(outlineMapper);
// Visualize
vtkSmartPointer<vtkRenderer> renderer =
vtkSmartPointer<vtkRenderer>::New();
vtkSmartPointer<vtkRenderWindow> renderWindow =
vtkSmartPointer<vtkRenderWindow>::New();
renderWindow->AddRenderer(renderer);
vtkSmartPointer<vtkRenderWindowInteractor> interactor =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
interactor->SetRenderWindow(renderWindow);
renderer->AddActor(contourActor);
renderer->AddActor(outlineActor);
vtkSmartPointer<vtkSliderRepresentation3D> sliderRep =
vtkSmartPointer<vtkSliderRepresentation3D>::New();
sliderRep->SetMinimumValue(0.0);
sliderRep->SetMaximumValue(30.0);
sliderRep->SetValue(10.0);
sliderRep->SetTitleText("Contour value");
sliderRep->SetPoint1InWorldCoordinates(-20, -40, 0);
sliderRep->SetPoint2InWorldCoordinates(0, -40, 0);
sliderRep->SetSliderWidth(.2);
sliderRep->SetLabelHeight(.1);
vtkSmartPointer<vtkSliderWidget> sliderWidget =
vtkSmartPointer<vtkSliderWidget>::New();
sliderWidget->SetInteractor(interactor);
sliderWidget->SetRepresentation(sliderRep);
sliderWidget->SetAnimationModeToAnimate();
sliderWidget->EnabledOn();
vtkSmartPointer<vtkSliderCallback> callback =
vtkSmartPointer<vtkSliderCallback>::New();
callback->ContourFilter = contourFilter;
sliderWidget->AddObserver(vtkCommand::InteractionEvent,callback);
vtkSmartPointer<vtkInteractorStyleUser> style =
vtkSmartPointer<vtkInteractorStyleUser>::New();
interactor->SetInteractorStyle(style);
renderWindow->SetSize(500,500);
renderWindow->Render();
renderWindow->Render();
interactor->Start();
return EXIT_SUCCESS;
}
void CreateData(vtkImageData* data)
{
data->SetExtent(-25,25,-25,25,0,0);
#if VTK_MAJOR_VERSION <= 5
data->SetNumberOfScalarComponents(1);
data->SetScalarTypeToDouble();
#else
data->AllocateScalars(VTK_DOUBLE,1);
#endif
int* extent = data->GetExtent();
for (int y = extent[2]; y <= extent[3]; y++)
{
for (int x = extent[0]; x <= extent[1]; x++)
{
double* pixel = static_cast<double*>(data->GetScalarPointer(x,y,0));
pixel[0] = sqrt(pow(x,2.0) + pow(y,2.0));
}
}
vtkSmartPointer<vtkXMLImageDataWriter> writer =
vtkSmartPointer<vtkXMLImageDataWriter>::New();
writer->SetFileName("data.vti");
#if VTK_MAJOR_VERSION <= 5
writer->SetInputConnection(data->GetProducerPort());
#else
writer->SetInputData(data);
#endif
writer->Write();
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(IsoContours)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(IsoContours MACOSX_BUNDLE IsoContours.cxx)
target_link_libraries(IsoContours ${VTK_LIBRARIES})
Download and Build IsoContours
Click here to download IsoContours and its CMakeLists.txt file. Once the tarball IsoContours.tar has been downloaded and extracted,
cd IsoContours/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:
./IsoContours
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.