ExtractSurface
VTKExamples/Cxx/Points/ExtractSurface
Description¶
This example loosely follows the most excellent paper by Curless and Levoy: "A Volumetric Method for Building Complex Models from Range Images." First it estimates normals from the points, then creates a signed distance field, followed by surface extraction of the zero-level set of the distance field.
The image was created using the Armadillo dataset
Warning
The classes used in this example require vtk 7.1 or later.
Code¶
ExtractSurface.cxx
#include <vtkSmartPointer.h> #include <vtkPLYReader.h> #include <vtkXMLPolyDataReader.h> #include <vtkOBJReader.h> #include <vtkSTLReader.h> #include <vtkPointSource.h> #include <vtkPCANormalEstimation.h> #include <vtkSignedDistance.h> #include <vtkExtractSurface.h> #include <vtkPointData.h> #include <vtkPolyDataMapper.h> #include <vtkProperty.h> #include <vtkRenderWindow.h> #include <vtkRenderWindowInteractor.h> #include <vtkRenderer.h> #include <vtkCamera.h> #include <vtksys/SystemTools.hxx> static vtkSmartPointer<vtkPolyData> ReadPolyData(const char *fileName); int main (int argc, char *argv[]) { vtkSmartPointer<vtkPolyData> polyData = ReadPolyData(argc > 1 ? argv[1] : "");; double bounds[6]; polyData->GetBounds(bounds); double range[3]; for (int i = 0; i < 3; ++i) { range[i] = bounds[2*i + 1] - bounds[2*i]; } int sampleSize = polyData->GetNumberOfPoints() * .00005; if (sampleSize < 10) { sampleSize = 10; } std::cout << "Sample size is: " << sampleSize << std::endl; // Do we need to estimate normals? vtkSmartPointer<vtkSignedDistance> distance = vtkSmartPointer<vtkSignedDistance>::New(); if (polyData->GetPointData()->GetNormals()) { std::cout << "Using normals from input file" << std::endl; distance->SetInputData (polyData); } else { std::cout << "Estimating normals using PCANormalEstimation" << std::endl; vtkSmartPointer<vtkPCANormalEstimation> normals = vtkSmartPointer<vtkPCANormalEstimation>::New(); normals->SetInputData (polyData); normals->SetSampleSize(sampleSize); normals->SetNormalOrientationToGraphTraversal(); normals->FlipNormalsOn(); distance->SetInputConnection (normals->GetOutputPort()); } std::cout << "Range: " << range[0] << ", " << range[1] << ", " << range[2] << std::endl; int dimension = 256; double radius = range[0] * .02; radius = range[0] / static_cast<double>(dimension) * 3; // ~3 voxels std::cout << "Radius: " << radius << std::endl; distance->SetRadius(radius); distance->SetDimensions(dimension, dimension, dimension); distance->SetBounds( bounds[0] - range[0] * .1, bounds[1] + range[0] * .1, bounds[2] - range[1] * .1, bounds[3] + range[1] * .1, bounds[4] - range[2] * .1, bounds[5] + range[2] * .1); vtkSmartPointer<vtkExtractSurface> surface = vtkSmartPointer<vtkExtractSurface>::New(); surface->SetInputConnection (distance->GetOutputPort()); surface->SetRadius(radius * .99); surface->Update(); vtkSmartPointer<vtkPolyDataMapper> surfaceMapper = vtkSmartPointer<vtkPolyDataMapper>::New(); surfaceMapper->SetInputConnection(surface->GetOutputPort()); vtkSmartPointer<vtkActor> surfaceActor = vtkSmartPointer<vtkActor>::New(); surfaceActor->SetMapper(surfaceMapper); surfaceActor->GetProperty()->SetColor(1.0000,0.3882,0.2784); // Create graphics stuff // vtkSmartPointer<vtkRenderer> ren1 = vtkSmartPointer<vtkRenderer>::New(); ren1->SetBackground(.3, .4, .6); vtkSmartPointer<vtkRenderWindow> renWin = vtkSmartPointer<vtkRenderWindow>::New(); renWin->AddRenderer(ren1); renWin->SetSize(512,512); vtkSmartPointer<vtkRenderWindowInteractor> iren = vtkSmartPointer<vtkRenderWindowInteractor>::New(); iren->SetRenderWindow(renWin); // Add the actors to the renderer, set the background and size // ren1->AddActor(surfaceActor); // Generate an interesting view // ren1->ResetCamera(); ren1->GetActiveCamera()->Azimuth(120); ren1->GetActiveCamera()->Elevation(30); ren1->GetActiveCamera()->Dolly(1.0); ren1->ResetCameraClippingRange(); iren->Initialize(); iren->Start(); return EXIT_SUCCESS; } static vtkSmartPointer<vtkPolyData> ReadPolyData(const char *fileName) { vtkSmartPointer<vtkPolyData> polyData; std::string extension = vtksys::SystemTools::GetFilenameExtension(std::string(fileName)); if (extension == ".ply") { vtkSmartPointer<vtkPLYReader> reader = vtkSmartPointer<vtkPLYReader>::New(); reader->SetFileName (fileName); reader->Update(); polyData = reader->GetOutput(); } else if (extension == ".vtp") { vtkSmartPointer<vtkXMLPolyDataReader> reader = vtkSmartPointer<vtkXMLPolyDataReader>::New(); reader->SetFileName (fileName); reader->Update(); polyData = reader->GetOutput(); } else if (extension == ".obj") { vtkSmartPointer<vtkOBJReader> reader = vtkSmartPointer<vtkOBJReader>::New(); reader->SetFileName (fileName); reader->Update(); polyData = reader->GetOutput(); } else if (extension == ".stl") { vtkSmartPointer<vtkSTLReader> reader = vtkSmartPointer<vtkSTLReader>::New(); reader->SetFileName (fileName); reader->Update(); polyData = reader->GetOutput(); } else { vtkSmartPointer<vtkPointSource> points = vtkSmartPointer<vtkPointSource>::New(); points->SetNumberOfPoints(100000); points->SetRadius(10.0); points->SetCenter(vtkMath::Random(-100, 100), vtkMath::Random(-100, 100), vtkMath::Random(-100, 100)); points->SetDistributionToShell(); points->Update(); polyData = points->GetOutput(); } return polyData; }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(ExtractSurface) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(ExtractSurface MACOSX_BUNDLE ExtractSurface.cxx) target_link_libraries(ExtractSurface ${VTK_LIBRARIES})
Download and Build ExtractSurface¶
Danger
The generation of tar files has not been ported to the new VTKExamples. Some tarballs may be missing or out-of-date.
Click here to download ExtractSurface and its CMakeLists.txt file. Once the tarball ExtractSurface.tar has been downloaded and extracted,
cd ExtractSurface/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:
./ExtractSurface
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.