vtkPolygonalSurfaceContourLineInterpolator 多边形曲面上的多边形绘制器

 【类简介】

在多边形曲面上实现轮廓点的交互绘制。

该类主要是实现在多边形曲面上绘制、移动轮廓点。该类插入的节点主要是用多边形数据来计算图像的测地距离，也就是说两点之间连线的是沿着几何表面的最短路径，使用Dijkstra算法。

该类的使用需要结合 vtkPolygonalSurfacePointPlacer 类，定位点的功能也就是拾取器。

前提：输入的多边形曲面需要计算法向量。

【示例】

</pre><pre code_snippet_id="1970532" snippet_file_name="blog_20161107_16_2205487" name="code" class="cpp">#include <vtkVersion.h>#include "vtkSmartPointer.h" #include "vtkActor.h"#include "vtkCamera.h"#include "vtkCellArray.h"#include "vtkImageDataGeometryFilter.h"#include "vtkPoints.h"#include "vtkPolyData.h"#include "vtkPolyDataCollection.h"#include "vtkPolyDataMapper.h"#include "vtkProperty.h"#include "vtkRenderWindow.h"#include "vtkRenderWindowInteractor.h"#include "vtkRenderer.h"#include "vtkSphereSource.h"#include "vtkTriangleFilter.h"#include "vtkXMLPolyDataReader.h" #include "vtkContourWidget.h"#include "vtkOrientedGlyphContourRepresentation.h"#include "vtkPolygonalSurfacePointPlacer.h"#include "vtkPolygonalSurfaceContourLineInterpolator.h"  int main(int argc, char *argv[]){  vtkSmartPointer<vtkPolyData> polyData;  if (argc < 2)    {    vtkSmartPointer<vtkSphereSource> sphereSource =       vtkSmartPointer<vtkSphereSource>::New();    sphereSource->SetThetaResolution(40);    sphereSource->SetPhiResolution(20);    sphereSource->Update();     polyData = sphereSource->GetOutput();    }  else    {    vtkSmartPointer<vtkXMLPolyDataReader> reader =       vtkSmartPointer<vtkXMLPolyDataReader>::New();    reader->SetFileName(argv[1]);    reader->Update();    polyData = reader->GetOutput();    }   // The Dijkistra interpolator will not accept cells that aren't triangles  vtkSmartPointer<vtkTriangleFilter> triangleFilter =     vtkSmartPointer<vtkTriangleFilter>::New();#if VTK_MAJOR_VERSION <= 5  triangleFilter->SetInput( polyData );#else  triangleFilter->SetInputData( polyData );#endif  triangleFilter->Update();   vtkSmartPointer<vtkPolyData> pd = triangleFilter->GetOutput();   //Create a mapper and actor  vtkSmartPointer<vtkPolyDataMapper> mapper =     vtkSmartPointer<vtkPolyDataMapper>::New();  mapper->SetInputConnection(triangleFilter->GetOutputPort());   vtkSmartPointer<vtkActor> actor =     vtkSmartPointer<vtkActor>::New();  actor->SetMapper(mapper);  actor->GetProperty()->SetInterpolationToFlat();   // Create the render window, renderer and interactor.   vtkSmartPointer<vtkRenderer> renderer =     vtkSmartPointer<vtkRenderer>::New();  vtkSmartPointer<vtkRenderWindow> renderWindow =     vtkSmartPointer<vtkRenderWindow>::New();  renderWindow->AddRenderer(renderer);  vtkSmartPointer<vtkRenderWindowInteractor> interactor =     vtkSmartPointer<vtkRenderWindowInteractor>::New();  interactor->SetRenderWindow(renderWindow);   // Add the actors to the renderer, set the background and size   renderer->AddActor(actor);  renderer->SetBackground (.3, .4, .5);   // Here comes the contour widget stuff...   vtkSmartPointer<vtkContourWidget> contourWidget =     vtkSmartPointer<vtkContourWidget>::New();  contourWidget->SetInteractor(interactor);  vtkSmartPointer<vtkOrientedGlyphContourRepresentation> rep =     vtkOrientedGlyphContourRepresentation::SafeDownCast(      contourWidget->GetRepresentation());  rep->GetLinesProperty()->SetColor(1, 0.2, 0);  rep->GetLinesProperty()->SetLineWidth(3.0);   vtkSmartPointer<vtkPolygonalSurfacePointPlacer> pointPlacer =    vtkSmartPointer<vtkPolygonalSurfacePointPlacer>::New();  pointPlacer->AddProp(actor);  pointPlacer->GetPolys()->AddItem( pd );  rep->SetPointPlacer(pointPlacer);   vtkSmartPointer<vtkPolygonalSurfaceContourLineInterpolator> interpolator =    vtkSmartPointer<vtkPolygonalSurfaceContourLineInterpolator>::New();  interpolator->GetPolys()->AddItem( pd );  rep->SetLineInterpolator(interpolator);   renderWindow->Render();  interactor->Initialize();   contourWidget->EnabledOn();   interactor->Start();   return EXIT_SUCCESS;}