# PolyLine

vtk-examples/Cxx/GeometricObjects/PolyLine

### Description¶

The polyline is a composite one-dimensional cell consisting of one or more connected lines. The polyline is defined by an ordered list of n+1 points, where n is the number of lines in the polyline. Each pair of points (i, i+1) defines a line.

Other languages

See (Python), (CSharp)

Question

### Code¶

PolyLine.cxx

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

int main(int, char*[])
{
vtkNew<vtkNamedColors> colors;

// 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);

vtkNew<vtkPolyLine> polyLine;
polyLine->GetPointIds()->SetNumberOfIds(5);
for (unsigned int i = 0; i < 5; i++)
{
polyLine->GetPointIds()->SetId(i, i);
}

// Create a cell array to store the lines in and add the lines to it
vtkNew<vtkCellArray> cells;
cells->InsertNextCell(polyLine);

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

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

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

// Setup actor and mapper
vtkNew<vtkPolyDataMapper> mapper;
mapper->SetInputData(polyData);

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

// Setup render window, renderer, and interactor
vtkNew<vtkRenderer> renderer;
vtkNew<vtkRenderWindow> renderWindow;
renderWindow->SetWindowName("PolyLine");
vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
renderWindowInteractor->SetRenderWindow(renderWindow);
renderer->SetBackground(colors->GetColor3d("DarkOliveGreen").GetData());

renderWindow->Render();
renderWindowInteractor->Start();

return EXIT_SUCCESS;
}


### CMakeLists.txt¶

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(PolyLine)

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

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


cd PolyLine/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:

./PolyLine


WINDOWS USERS

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