IterativeClosestPointsTransform
VTKExamples/Cxx/Filtering/IterativeClosestPointsTransform
Description¶
This demo produces target points (green) which are at the origin and unit length along each axis. It then perturbs the points and shifts each of them .3 in +y direction - the resulting points are the "source" points (red). It then attempts to move the source points as close as possible to the target points. The resulting points are shown in blue. The noise is added to make the example more realistic. Also, the noise ensures nothing was done wrong (i.e. accidentally using the target points as the result and claiming it worked perfectly when in fact nothing happened!)
Code¶
IterativeClosestPointsTransform.cxx
#include <vtkVersion.h> #include <vtkSmartPointer.h> #include <vtkTransform.h> #include <vtkVertexGlyphFilter.h> #include <vtkPoints.h> #include <vtkPolyData.h> #include <vtkCellArray.h> #include <vtkIterativeClosestPointTransform.h> #include <vtkTransformPolyDataFilter.h> #include <vtkLandmarkTransform.h> #include <vtkMath.h> #include <vtkMatrix4x4.h> #include <vtkXMLPolyDataWriter.h> #include <vtkPolyDataMapper.h> #include <vtkActor.h> #include <vtkRenderWindow.h> #include <vtkRenderer.h> #include <vtkRenderWindowInteractor.h> #include <vtkXMLPolyDataReader.h> #include <vtkProperty.h> namespace { void CreatePolyData(vtkSmartPointer<vtkPolyData> polydata); void PerturbPolyData(vtkSmartPointer<vtkPolyData> polydata); void TranslatePolyData(vtkSmartPointer<vtkPolyData> polydata); } int main(int argc, char *argv[]) { vtkSmartPointer<vtkPolyData> source = vtkSmartPointer<vtkPolyData>::New(); vtkSmartPointer<vtkPolyData> target = vtkSmartPointer<vtkPolyData>::New(); if(argc == 3) { std::cout << "Reading data..." << std::endl; std::string strSource = argv[1]; std::string strTarget = argv[2]; vtkSmartPointer<vtkXMLPolyDataReader> sourceReader = vtkSmartPointer<vtkXMLPolyDataReader>::New(); sourceReader->SetFileName(strSource.c_str()); sourceReader->Update(); source->ShallowCopy(sourceReader->GetOutput()); vtkSmartPointer<vtkXMLPolyDataReader> targetReader = vtkSmartPointer<vtkXMLPolyDataReader>::New(); targetReader->SetFileName(strTarget.c_str()); targetReader->Update(); target->ShallowCopy(targetReader->GetOutput()); } else { std::cout << "Creating data..." << std::endl; CreatePolyData(source); target->ShallowCopy(source); TranslatePolyData(target); PerturbPolyData(target); } // Setup ICP transform vtkSmartPointer<vtkIterativeClosestPointTransform> icp = vtkSmartPointer<vtkIterativeClosestPointTransform>::New(); icp->SetSource(source); icp->SetTarget(target); icp->GetLandmarkTransform()->SetModeToRigidBody(); icp->SetMaximumNumberOfIterations(20); //icp->StartByMatchingCentroidsOn(); icp->Modified(); icp->Update(); // Get the resulting transformation matrix (this matrix takes the source points to the target points) vtkSmartPointer<vtkMatrix4x4> m = icp->GetMatrix(); std::cout << "The resulting matrix is: " << *m << std::endl; // Transform the source points by the ICP solution vtkSmartPointer<vtkTransformPolyDataFilter> icpTransformFilter = vtkSmartPointer<vtkTransformPolyDataFilter>::New(); #if VTK_MAJOR_VERSION <= 5 icpTransformFilter->SetInput(source); #else icpTransformFilter->SetInputData(source); #endif icpTransformFilter->SetTransform(icp); icpTransformFilter->Update(); /* // If you need to take the target points to the source points, the matrix is: icp->Inverse(); vtkSmartPointer<vtkMatrix4x4> minv = icp->GetMatrix(); std::cout << "The resulting inverse matrix is: " << *minv << std::cout; */ // Visualize vtkSmartPointer<vtkPolyDataMapper> sourceMapper = vtkSmartPointer<vtkPolyDataMapper>::New(); #if VTK_MAJOR_VERSION <= 5 sourceMapper->SetInputConnection(source->GetProducerPort()); #else sourceMapper->SetInputData(source); #endif vtkSmartPointer<vtkActor> sourceActor = vtkSmartPointer<vtkActor>::New(); sourceActor->SetMapper(sourceMapper); sourceActor->GetProperty()->SetColor(1,0,0); sourceActor->GetProperty()->SetPointSize(4); vtkSmartPointer<vtkPolyDataMapper> targetMapper = vtkSmartPointer<vtkPolyDataMapper>::New(); #if VTK_MAJOR_VERSION <= 5 targetMapper->SetInputConnection(target->GetProducerPort()); #else targetMapper->SetInputData(target); #endif vtkSmartPointer<vtkActor> targetActor = vtkSmartPointer<vtkActor>::New(); targetActor->SetMapper(targetMapper); targetActor->GetProperty()->SetColor(0,1,0); targetActor->GetProperty()->SetPointSize(4); vtkSmartPointer<vtkPolyDataMapper> solutionMapper = vtkSmartPointer<vtkPolyDataMapper>::New(); solutionMapper->SetInputConnection(icpTransformFilter->GetOutputPort()); vtkSmartPointer<vtkActor> solutionActor = vtkSmartPointer<vtkActor>::New(); solutionActor->SetMapper(solutionMapper); solutionActor->GetProperty()->SetColor(0,0,1); solutionActor->GetProperty()->SetPointSize(3); // Create a renderer, render window, and interactor vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New(); vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New(); renderWindow->AddRenderer(renderer); vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = vtkSmartPointer<vtkRenderWindowInteractor>::New(); renderWindowInteractor->SetRenderWindow(renderWindow); // Add the actor to the scene renderer->AddActor(sourceActor); renderer->AddActor(targetActor); renderer->AddActor(solutionActor); renderer->SetBackground(.3, .6, .3); // Background color green // Render and interact renderWindow->Render(); renderWindowInteractor->Start(); return EXIT_SUCCESS; } namespace // anonymous { void CreatePolyData(vtkSmartPointer<vtkPolyData> polydata) { // This function creates a set of 4 points (the origin and a point unit distance along each axis) vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New(); // Create points double origin[3] = {0.0, 0.0, 0.0}; points->InsertNextPoint(origin); double p1[3] = {1.0, 0.0, 0.0}; points->InsertNextPoint(p1); double p2[3] = {0.0, 1.0, 0.0}; points->InsertNextPoint(p2); double p3[3] = {0.0, 0.0, 1.0}; points->InsertNextPoint(p3); vtkSmartPointer<vtkPolyData> temp = vtkSmartPointer<vtkPolyData>::New(); temp->SetPoints(points); vtkSmartPointer<vtkVertexGlyphFilter> vertexFilter = vtkSmartPointer<vtkVertexGlyphFilter>::New(); #if VTK_MAJOR_VERSION <= 5 vertexFilter->SetInputConnection(temp->GetProducerPort()); #else vertexFilter->SetInputData(temp); #endif vertexFilter->Update(); polydata->ShallowCopy(vertexFilter->GetOutput()); } void PerturbPolyData(vtkSmartPointer<vtkPolyData> polydata) { vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New(); points->ShallowCopy(polydata->GetPoints()); for(vtkIdType i = 0; i < points->GetNumberOfPoints(); i++) { double p[3]; points->GetPoint(i, p); double perturb[3]; if(i%3 == 0) { perturb[0] = .1; perturb[1] = 0; perturb[2] = 0; } else if(i%3 == 1) { perturb[0] = 0; perturb[1] = .1; perturb[2] = 0; } else { perturb[0] = 0; perturb[1] = 0; perturb[2] = .1; } for(unsigned int j = 0; j < 3; j++) { p[j] += perturb[j]; } points->SetPoint(i, p); } polydata->SetPoints(points); } void TranslatePolyData(vtkSmartPointer<vtkPolyData> polydata) { vtkSmartPointer<vtkTransform> transform = vtkSmartPointer<vtkTransform>::New(); transform->Translate(0,.3,0); vtkSmartPointer<vtkTransformPolyDataFilter> transformFilter = vtkSmartPointer<vtkTransformPolyDataFilter>::New(); #if VTK_MAJOR_VERSION <= 5 transformFilter->SetInputConnection(polydata->GetProducerPort()); #else transformFilter->SetInputData(polydata); #endif transformFilter->SetTransform(transform); transformFilter->Update(); polydata->ShallowCopy(transformFilter->GetOutput()); } } // end anonymous namespace
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(IterativeClosestPointsTransform) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(IterativeClosestPointsTransform MACOSX_BUNDLE IterativeClosestPointsTransform.cxx) target_link_libraries(IterativeClosestPointsTransform ${VTK_LIBRARIES})
Download and Build IterativeClosestPointsTransform¶
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Click here to download IterativeClosestPointsTransform and its CMakeLists.txt file. Once the tarball IterativeClosestPointsTransform.tar has been downloaded and extracted,
cd IterativeClosestPointsTransform/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:
./IterativeClosestPointsTransform
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.