LongLine

VTKExamples/Cxx/GeometricObjects/LongLine


Description

Connect several points with a line.

Seealso

ColoredLines.

Other Languages

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

Question

If you have a simple question about this example contact us at VTKExamplesProject If your question is more complex and may require extended discussion, 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 <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkSmartPointer.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
  vtkSmartPointer<vtkPoints> points =
    vtkSmartPointer<vtkPoints>::New();
  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
  vtkSmartPointer<vtkCellArray> lines =
    vtkSmartPointer<vtkCellArray>::New();

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

  // Create a polydata to store everything in
  vtkSmartPointer<vtkPolyData> linesPolyData =
    vtkSmartPointer<vtkPolyData>::New();

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

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

  // Setup actor and mapper
  vtkSmartPointer<vtkNamedColors> colors =
    vtkSmartPointer<vtkNamedColors>::New();

  vtkSmartPointer<vtkPolyDataMapper> mapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  mapper->SetInputData(linesPolyData);

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

  // Setup render window, renderer, and interactor
  vtkSmartPointer<vtkRenderer> renderer =
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->SetWindowName("Long Line");
  renderWindow->AddRenderer(renderer);
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
      vtkSmartPointer<vtkRenderWindowInteractor>::New();
  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 3.3 FATAL_ERROR)

project(LongLine)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkInteractionStyle
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
  message("Skipping LongLine: ${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(LongLine MACOSX_BUNDLE LongLine.cxx )
  target_link_libraries(LongLine PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  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}
    )
endif () 

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.