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LongLine

vtk-examples/Cxx/GeometricObjects/LongLine


Description

Connect several points with a line.

Seealso

ColoredLines.

Other languages

See (Python), (Java), (CSharp)

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

LongLine.cxx

#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkCellArray.h>
#include <vtkCellData.h>
#include <vtkDoubleArray.h>
#include <vtkLine.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>

int main(int, char*[])
{
  // Create five points.
  double origin[3] = {0.0, 0.0, 0.0};
  double p0[3] = {1.0, 0.0, 0.0};
  double p1[3] = {0.0, 1.0, 0.0};
  double p2[3] = {0.0, 1.0, 2.0};
  double p3[3] = {1.0, 2.0, 3.0};

  // Create a vtkPoints object and store the points in it
  vtkNew<vtkPoints> points;
  points->InsertNextPoint(origin);
  points->InsertNextPoint(p0);
  points->InsertNextPoint(p1);
  points->InsertNextPoint(p2);
  points->InsertNextPoint(p3);

  // Create a cell array to store the lines in and add the lines to it
  vtkNew<vtkCellArray> lines;

  for (unsigned int i = 0; i < 3; i++)
  {
    vtkNew<vtkLine> line;
    line->GetPointIds()->SetId(0, i);
    line->GetPointIds()->SetId(1, i + 1);
    lines->InsertNextCell(line);
  }

  // Create a polydata to store everything in
  vtkNew<vtkPolyData> linesPolyData;

  // Add the points to the dataset
  linesPolyData->SetPoints(points);

  // Add the lines to the dataset
  linesPolyData->SetLines(lines);

  // Setup actor and mapper
  vtkNew<vtkNamedColors> colors;

  vtkNew<vtkPolyDataMapper> mapper;
  mapper->SetInputData(linesPolyData);

  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);
  actor->GetProperty()->SetLineWidth(4);
  actor->GetProperty()->SetColor(colors->GetColor3d("Peacock").GetData());

  // Setup render window, renderer, and interactor
  vtkNew<vtkRenderer> renderer;
  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->SetWindowName("LongLine");
  renderWindow->AddRenderer(renderer);
  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  renderWindowInteractor->SetRenderWindow(renderWindow);
  renderer->AddActor(actor);

  renderer->ResetCamera();
  renderer->GetActiveCamera()->Azimuth(30);
  renderer->GetActiveCamera()->Elevation(30);
  renderer->ResetCameraClippingRange();

  renderer->SetBackground(colors->GetColor3d("Silver").GetData());
  renderWindow->Render();
  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(LongLine)

find_package(VTK COMPONENTS 
  CommonColor
  CommonCore
  CommonDataModel
  InteractionStyle
  RenderingContextOpenGL2
  RenderingCore
  RenderingFreeType
  RenderingGL2PSOpenGL2
  RenderingOpenGL2
  QUIET
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "LongLine: 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(LongLine MACOSX_BUNDLE LongLine.cxx )
  target_link_libraries(LongLine PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS LongLine
  MODULES ${VTK_LIBRARIES}
)

Download and Build LongLine

Click here to download LongLine and its CMakeLists.txt file. Once the tarball LongLine.tar has been downloaded and extracted,

cd LongLine/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:

./LongLine

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.