Hello
VTKEx/Cxx/VisualizationAlgorithms/Hello
Description¶
Implicit modelling used to thicken a stroked font. Original lines can be seen within the translucent implicit surface.
Info
See Figure 6-28 in Chapter 6 the VTK Textbook.
Other languages
See (Python)
Question
If you have a simple question about this example contact us at VTKExProject If your question is more complex and may require extended discussion, please use the VTK Discourse Forum
Code¶
Hello.cxx
#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkContourFilter.h>
#include <vtkImplicitModeller.h>
#include <vtkNamedColors.h>
#include <vtkPolyDataMapper.h>
#include <vtkPolyDataReader.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
int main(int argc, char *argv[])
{
if (argc < 2)
{
std::cout << "Usage: " << argv[0] << " hello.vtk" << std::endl;
return EXIT_FAILURE;
}
vtkSmartPointer<vtkNamedColors> colors =
vtkSmartPointer<vtkNamedColors>::New();
// Create lines which serve as the "seed" geometry. The lines spell the
// word "hello".
//
vtkSmartPointer<vtkPolyDataReader> reader =
vtkSmartPointer<vtkPolyDataReader>::New();
reader->SetFileName(argv[1]);
vtkSmartPointer<vtkPolyDataMapper> lineMapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
lineMapper->SetInputConnection(reader->GetOutputPort());
vtkSmartPointer<vtkActor> lineActor =
vtkSmartPointer<vtkActor>::New();
lineActor->SetMapper(lineMapper);
lineActor->GetProperty()->SetColor(colors->GetColor3d("Tomato").GetData());
lineActor->GetProperty()->SetLineWidth(3.0);
// Create implicit model with vtkImplicitModeller. This computes a scalar
// field which is the distance from the generating geometry. The contour
// filter then extracts the geometry at the distance value 0.25 from the
// generating geometry.
//
vtkSmartPointer<vtkImplicitModeller> imp =
vtkSmartPointer<vtkImplicitModeller>::New();
imp->SetInputConnection(reader->GetOutputPort());
imp->SetSampleDimensions(110, 40, 20);
imp->SetMaximumDistance(0.25);
imp->SetModelBounds(-1.0, 10.0, -1.0, 3.0, -1.0, 1.0);
vtkSmartPointer<vtkContourFilter> contour =
vtkSmartPointer<vtkContourFilter>::New();
contour->SetInputConnection(imp->GetOutputPort());
contour->SetValue(0, 0.25);
vtkSmartPointer<vtkPolyDataMapper> impMapper =
vtkSmartPointer<vtkPolyDataMapper>::New();
impMapper->SetInputConnection(contour->GetOutputPort());
impMapper->ScalarVisibilityOff();
vtkSmartPointer<vtkActor> impActor =
vtkSmartPointer<vtkActor>::New();
impActor->SetMapper(impMapper);
impActor->GetProperty()->SetColor(colors->GetColor3d("Peacock").GetData());
impActor->GetProperty()->SetOpacity(0.5);
// Create the usual graphics stuff.
// Create the RenderWindow, Renderer and both Actors
//
vtkSmartPointer<vtkRenderer> ren1 =
vtkSmartPointer<vtkRenderer>::New();
vtkSmartPointer<vtkRenderWindow> renWin =
vtkSmartPointer<vtkRenderWindow>::New();
renWin->AddRenderer(ren1);
vtkSmartPointer<vtkRenderWindowInteractor> iren =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
iren->SetRenderWindow(renWin);
// Add the actors to the renderer, set the background and size
//
ren1->AddActor(lineActor);
ren1->AddActor(impActor);
ren1->SetBackground(colors->GetColor3d("Wheat").GetData());
renWin->SetSize(640, 480);
vtkSmartPointer<vtkCamera> camera =
vtkSmartPointer<vtkCamera>::New();
camera->SetFocalPoint(4.5, 1, 0);
camera->SetPosition(4.5, 1.0, 6.73257);
camera->SetViewUp(0, 1, 0);
ren1->SetActiveCamera(camera);
ren1->ResetCamera();
camera->Dolly(1.3);
camera->SetClippingRange(1.81325, 90.6627);
renWin->Render();
iren->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.3 FATAL_ERROR)
project(Hello)
find_package(VTK COMPONENTS
vtkvtkCommonColor
vtkvtkFiltersCore
vtkvtkFiltersHybrid
vtkvtkIOLegacy
vtkvtkInteractionStyle
vtkvtkRenderingContextOpenGL2
vtkvtkRenderingCore
vtkvtkRenderingFreeType
vtkvtkRenderingGL2PSOpenGL2
vtkvtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
message("Skipping Hello: ${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(Hello MACOSX_BUNDLE Hello.cxx )
target_link_libraries(Hello PRIVATE ${VTK_LIBRARIES})
else ()
# include all components
add_executable(Hello MACOSX_BUNDLE Hello.cxx )
target_link_libraries(Hello PRIVATE ${VTK_LIBRARIES})
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS Hello
MODULES ${VTK_LIBRARIES}
)
endif ()
Download and Build Hello¶
Click here to download Hello and its CMakeLists.txt file. Once the tarball Hello.tar has been downloaded and extracted,
cd Hello/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:
./Hello
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.