# ConvexPointSet

VTKExamples/Cxx/GeometricObjects/ConvexPointSet

### Description¶

vtkConvexPointSet object represents a 3D cell defined by a convex set of points. An example of such a cell is an octant (from an octree). vtkConvexPointSet uses the ordered triangulations approach vtkOrderedTriangulator) to create triangulations guaranteed to be compatible across shared faces.

Other Languages

See (Python), (Java)

Question

### Code¶

ConvexPointSet.cxx

#include <vtkActor.h>
#include <vtkCamera.h>
#include <vtkConvexPointSet.h>
#include <vtkDataSetMapper.h>
#include <vtkGlyph3DMapper.h>
#include <vtkNamedColors.h>
#include <vtkPoints.h>
#include <vtkProperty.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkShrinkFilter.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkUnstructuredGrid.h>

int main (int, char *[])
{
vtkSmartPointer<vtkConvexPointSet> cps =
vtkSmartPointer<vtkConvexPointSet>::New();
vtkSmartPointer<vtkPoints> points =
vtkSmartPointer<vtkPoints>::New();
points->InsertNextPoint( 0, 0, 0);
points->InsertNextPoint( 1, 0, 0);
points->InsertNextPoint( 1, 1, 0);
points->InsertNextPoint( 0, 1, 0);
points->InsertNextPoint( 0, 0, 1);
points->InsertNextPoint( 1, 0, 1);
points->InsertNextPoint( 1, 1, 1);
points->InsertNextPoint( 0, 1, 1);
points->InsertNextPoint( 0.5, 0, 0);
points->InsertNextPoint( 1, 0.5, 0);
points->InsertNextPoint( 0.5, 1, 0);
points->InsertNextPoint( 0, 0.5, 0);
points->InsertNextPoint( 0.5, 0.5, 0);

for (int i = 0; i < 13; ++i)
{
cps->GetPointIds()->InsertId(i,i);
}

vtkSmartPointer<vtkUnstructuredGrid> ug =
vtkSmartPointer<vtkUnstructuredGrid>::New();
ug->Allocate(1,1);
ug->InsertNextCell(cps->GetCellType(), cps->GetPointIds());
ug->SetPoints(points);

vtkSmartPointer<vtkNamedColors> colors =
vtkSmartPointer<vtkNamedColors>::New();

vtkSmartPointer<vtkDataSetMapper> mapper =
vtkSmartPointer<vtkDataSetMapper>::New();
mapper->SetInputData(ug);

vtkSmartPointer<vtkActor> actor =
vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
actor->GetProperty()->SetColor(colors->GetColor3d("Tomato").GetData());
actor->GetProperty()->SetLineWidth(3);
actor->GetProperty()->EdgeVisibilityOn();

// Glyph the points
vtkSmartPointer<vtkSphereSource> sphere =
vtkSmartPointer<vtkSphereSource>::New();
sphere->SetPhiResolution(21);
sphere->SetThetaResolution(21);

// Create a polydata to store everything in
vtkSmartPointer<vtkPolyData> polyData =
vtkSmartPointer<vtkPolyData>::New();
polyData->SetPoints(points);

vtkSmartPointer<vtkGlyph3DMapper> pointMapper =
vtkSmartPointer<vtkGlyph3DMapper>::New();
pointMapper->SetInputData(polyData);
pointMapper->SetSourceConnection(sphere->GetOutputPort());

vtkSmartPointer<vtkActor> pointActor =
vtkSmartPointer<vtkActor>::New();
pointActor->SetMapper(pointMapper);
pointActor->GetProperty()->SetColor(colors->GetColor3d("Peacock").GetData());

//Create a renderer, render window, and interactor
vtkSmartPointer<vtkRenderer> renderer =
vtkSmartPointer<vtkRenderer>::New();
vtkSmartPointer<vtkRenderWindow> renderWindow =
vtkSmartPointer<vtkRenderWindow>::New();
renderWindow->SetWindowName("Convex Point Set");
vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
vtkSmartPointer<vtkRenderWindowInteractor>::New();
renderWindowInteractor->SetRenderWindow(renderWindow);

//Add the actors to the scene
renderer->SetBackground(colors->GetColor3d("Silver").GetData());

renderer->ResetCamera();
renderer->GetActiveCamera()->Azimuth(210);
renderer->GetActiveCamera()->Elevation(30);
renderer->ResetCameraClippingRange();

//Render and interact
renderWindow->SetSize(640, 480);
renderWindow->Render();
renderWindowInteractor->Start();

return EXIT_SUCCESS;
}


### CMakeLists.txt¶

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(ConvexPointSet)

find_package(VTK COMPONENTS
vtkCommonColor
vtkCommonCore
vtkCommonDataModel
vtkFiltersGeneral
vtkInteractionStyle
vtkRenderingCore
vtkRenderingFreeType
vtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
message("Skipping ConvexPointSet: ${VTK_NOT_FOUND_MESSAGE}") return () endif() message (STATUS "VTK_VERSION:${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
# old system
include(${VTK_USE_FILE}) add_executable(ConvexPointSet MACOSX_BUNDLE ConvexPointSet.cxx ) target_link_libraries(ConvexPointSet PRIVATE${VTK_LIBRARIES})
else ()
# include all components
target_link_libraries(ConvexPointSet PRIVATE ${VTK_LIBRARIES}) # vtk_module_autoinit is needed vtk_module_autoinit( TARGETS ConvexPointSet MODULES${VTK_LIBRARIES}
)
endif ()


cd ConvexPointSet/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:

./ConvexPointSet


WINDOWS USERS

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