Hello
Repository source: 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 question about this example, 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 <vtkNew.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;
}
vtkNew<vtkNamedColors> colors;
// Create lines which serve as the "seed" geometry. The lines spell the
// word "hello".
//
vtkNew<vtkPolyDataReader> reader;
reader->SetFileName(argv[1]);
vtkNew<vtkPolyDataMapper> lineMapper;
lineMapper->SetInputConnection(reader->GetOutputPort());
vtkNew<vtkActor> lineActor;
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.
//
vtkNew<vtkImplicitModeller> imp;
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);
vtkNew<vtkContourFilter> contour;
contour->SetInputConnection(imp->GetOutputPort());
contour->SetValue(0, 0.25);
vtkNew<vtkPolyDataMapper> impMapper;
impMapper->SetInputConnection(contour->GetOutputPort());
impMapper->ScalarVisibilityOff();
vtkNew<vtkActor> impActor;
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
//
vtkNew<vtkRenderer> ren1;
vtkNew<vtkRenderWindow> renWin;
renWin->AddRenderer(ren1);
vtkNew<vtkRenderWindowInteractor> iren;
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);
renWin->SetWindowName("Hello");
vtkNew<vtkCamera> camera;
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 3.12 FATAL_ERROR)
project(Hello)
find_package(VTK COMPONENTS
CommonColor
CommonCore
FiltersCore
FiltersHybrid
IOLegacy
InteractionStyle
RenderingContextOpenGL2
RenderingCore
RenderingFreeType
RenderingGL2PSOpenGL2
RenderingOpenGL2
)
if (NOT VTK_FOUND)
message(FATAL_ERROR "Hello: 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(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}
)
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.