LandmarkTransform
VTKExamples/Cxx/Filtering/LandmarkTransform
Description¶
This example creates two point sets which it assumes are known, ordered correspondences. It then transforms Source to Target and displays the matrix used in the transformation.
Code¶
LandmarkTransform.cxx
#include <vtkVersion.h> #include <vtkPoints.h> #include <vtkSmartPointer.h> #include <vtkLandmarkTransform.h> #include <vtkMatrix4x4.h> #include <vtkPolyDataMapper.h> #include <vtkActor.h> #include <vtkRenderWindow.h> #include <vtkRenderer.h> #include <vtkRenderWindowInteractor.h> #include <vtkProperty.h> #include <vtkTransformPolyDataFilter.h> #include <vtkVertexGlyphFilter.h> int main(int, char *[]) { /* This demo creates a coordinate frame (+x, +y, +z) of vectors and a rotated, peturbed frame (+z, +y, -x) and aligns the rotated frame to the original as best as possible. */ vtkSmartPointer<vtkPoints> sourcePoints = vtkSmartPointer<vtkPoints>::New(); double sourcePoint1[3] = {1.0, 0.0, 0.0}; sourcePoints->InsertNextPoint(sourcePoint1); double sourcePoint2[3] = {0.0, 1.0, 0.0}; sourcePoints->InsertNextPoint(sourcePoint2); double sourcePoint3[3] = {0.0, 0.0, 1.0}; sourcePoints->InsertNextPoint(sourcePoint3); vtkSmartPointer<vtkPoints> targetPoints = vtkSmartPointer<vtkPoints>::New(); double targetPoint1[3] = {0.0, 0.0, 1.1}; targetPoints->InsertNextPoint(targetPoint1); double targetPoint2[3] = {0.0, 1.02, 0.0}; targetPoints->InsertNextPoint(targetPoint2); double targetPoint3[3] = {-1.11, 0.0, 0.0}; targetPoints->InsertNextPoint(targetPoint3); // Setup the transform vtkSmartPointer<vtkLandmarkTransform> landmarkTransform = vtkSmartPointer<vtkLandmarkTransform>::New(); landmarkTransform->SetSourceLandmarks(sourcePoints); landmarkTransform->SetTargetLandmarks(targetPoints); landmarkTransform->SetModeToRigidBody(); landmarkTransform->Update(); //should this be here? vtkSmartPointer<vtkPolyData> source = vtkSmartPointer<vtkPolyData>::New(); source->SetPoints(sourcePoints); vtkSmartPointer<vtkPolyData> target = vtkSmartPointer<vtkPolyData>::New(); target->SetPoints(targetPoints); vtkSmartPointer<vtkVertexGlyphFilter> sourceGlyphFilter = vtkSmartPointer<vtkVertexGlyphFilter>::New(); #if VTK_MAJOR_VERSION <= 5 sourceGlyphFilter->SetInputConnection(source->GetProducerPort()); #else sourceGlyphFilter->SetInputData(source); #endif sourceGlyphFilter->Update(); vtkSmartPointer<vtkVertexGlyphFilter> targetGlyphFilter = vtkSmartPointer<vtkVertexGlyphFilter>::New(); #if VTK_MAJOR_VERSION <= 5 targetGlyphFilter->SetInputConnection(target->GetProducerPort()); #else targetGlyphFilter->SetInputData(target); #endif targetGlyphFilter->Update(); vtkSmartPointer<vtkTransformPolyDataFilter> transformFilter = vtkSmartPointer<vtkTransformPolyDataFilter>::New(); transformFilter->SetInputConnection(sourceGlyphFilter->GetOutputPort()); transformFilter->SetTransform(landmarkTransform); transformFilter->Update(); // Display the transformation matrix that was computed vtkMatrix4x4* mat = landmarkTransform->GetMatrix(); std::cout << "Matrix: " << *mat << std::endl; // Visualize vtkSmartPointer<vtkPolyDataMapper> sourceMapper = vtkSmartPointer<vtkPolyDataMapper>::New(); sourceMapper->SetInputConnection(sourceGlyphFilter->GetOutputPort()); vtkSmartPointer<vtkActor> sourceActor = vtkSmartPointer<vtkActor>::New(); sourceActor->SetMapper(sourceMapper); sourceActor->GetProperty()->SetColor(0,1,0); sourceActor->GetProperty()->SetPointSize(4); vtkSmartPointer<vtkPolyDataMapper> targetMapper = vtkSmartPointer<vtkPolyDataMapper>::New(); targetMapper->SetInputConnection(targetGlyphFilter->GetOutputPort()); vtkSmartPointer<vtkActor> targetActor = vtkSmartPointer<vtkActor>::New(); targetActor->SetMapper(targetMapper); targetActor->GetProperty()->SetColor(1,0,0); targetActor->GetProperty()->SetPointSize(4); vtkSmartPointer<vtkPolyDataMapper> solutionMapper = vtkSmartPointer<vtkPolyDataMapper>::New(); solutionMapper->SetInputConnection(transformFilter->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; }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(LandmarkTransform) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(LandmarkTransform MACOSX_BUNDLE LandmarkTransform.cxx) target_link_libraries(LandmarkTransform ${VTK_LIBRARIES})
Download and Build LandmarkTransform¶
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 LandmarkTransform and its CMakeLists.txt file. Once the tarball LandmarkTransform.tar has been downloaded and extracted,
cd LandmarkTransform/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:
./LandmarkTransform
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.