ConvexHullShrinkWrap
VTKExamples/Cxx/PolyData/ConvexHullShrinkWrap
Description
This example creates a point cloud, and a sphere larger than the point cloud which fully contains the cloud. It then "shrink wraps" the sphere onto the points. This produces approximately a convex hull.
Code
ConvexHullShrinkWrap.cxx
#include <vtkSmartPointer.h>
#include <vtkPolyData.h>
#include <vtkSphereSource.h>
#include <vtkPointSource.h>
#include <vtkSmoothPolyDataFilter.h>
#include <vtkXMLPolyDataWriter.h>
int main(int, char *[])
{
vtkSmartPointer<vtkSphereSource> sphereSource =
vtkSmartPointer<vtkSphereSource>::New();
sphereSource->SetRadius(10);
sphereSource->SetPhiResolution(50);
sphereSource->SetThetaResolution(50);
sphereSource->Update();
vtkSmartPointer<vtkPointSource> pointSource =
vtkSmartPointer<vtkPointSource>::New();
pointSource->SetNumberOfPoints(40);
pointSource->SetRadius(2);
pointSource->Update();
{
vtkSmartPointer<vtkXMLPolyDataWriter> writer =
vtkSmartPointer<vtkXMLPolyDataWriter>::New();
writer->SetFileName("input.vtp");
writer->SetInputConnection(sphereSource->GetOutputPort());
writer->Write();
}
{
vtkSmartPointer<vtkXMLPolyDataWriter> writer =
vtkSmartPointer<vtkXMLPolyDataWriter>::New();
writer->SetFileName("points.vtp");
writer->SetInputConnection(pointSource->GetOutputPort());
writer->Write();
}
vtkSmartPointer<vtkSmoothPolyDataFilter> smoothFilter =
vtkSmartPointer<vtkSmoothPolyDataFilter>::New();
smoothFilter->SetInputConnection(0, sphereSource->GetOutputPort());
smoothFilter->SetInputConnection(1, pointSource->GetOutputPort());
smoothFilter->Update();
vtkSmartPointer<vtkXMLPolyDataWriter> writer =
vtkSmartPointer<vtkXMLPolyDataWriter>::New();
writer->SetFileName("output.vtp");
writer->SetInputConnection(smoothFilter->GetOutputPort());
writer->Write();
return EXIT_SUCCESS;
}
CMakeLists.txt
cmake_minimum_required(VERSION 2.8)
PROJECT(ConvexHullShrinkWrap)
find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
add_executable(ConvexHullShrinkWrap MACOSX_BUNDLE ConvexHullShrinkWrap.cxx)
target_link_libraries(ConvexHullShrinkWrap ${VTK_LIBRARIES})
Download and Build ConvexHullShrinkWrap
Click here to download ConvexHullShrinkWrap and its CMakeLists.txt file. Once the tarball ConvexHullShrinkWrap.tar has been downloaded and extracted,
cd ConvexHullShrinkWrap/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:
./ConvexHullShrinkWrap
WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.