VTK 图形基本操作进阶_表面重建技术（三维点云曲面重建）

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mb5ff9827b65e5b 2021-01-06 16:35:00

文章标签 #include 点云数据邻域 3d 文章分类 代码人生

虽然Delaunay三角剖分算法可以实现网格曲面重建，但是其应用主要在二维剖分，在三维空间网格生成中遇到了问题。因为在三维点云曲面重建中，Delaunay条件不在满足，不仅基于最大最小角判断的对角线交换准则不在成立，而且基于外接圆判据的Delaunay三角化也不能保证网格质量。

VTKSurfaceReconstructionFilter则实现了一种隐式曲面重建方法，即将曲面看做一个符号距离函数的等值面，曲面内外的距离值得符号相反，而零等值面即为所求的曲面。该方法需要对点云数据进行网格划分，然后估算每个点的切平面和方向，并以每个点与最近的切平面距离来近似表面距离。这样即可得到一个符号距离的体数据。这样，我们就可以利用VTKContourFilter来提取零等值面即可得到相应的网格。

利用人脸点云数据进行人脸网格曲面重建实例如下：

  1 #include <vtkAutoInit.h>
  2 VTK_MODULE_INIT(vtkRenderingOpenGL);
  3 VTK_MODULE_INIT(vtkRenderingFreeType);
  4 VTK_MODULE_INIT(vtkInteractionStyle);
  5  
  6 #include <vtkSmartPointer.h>
  7 #include <vtkPolyDataReader.h>
  8 #include <vtkPolyData.h>
  9 #include <vtkSurfaceReconstructionFilter.h>
 10 #include <vtkContourFilter.h>
 11 #include <vtkVertexGlyphFilter.h>
 12 #include <vtkPolyDataMapper.h>
 13 #include <vtkActor.h>
 14 #include <vtkRenderer.h>
 15 #include <vtkCamera.h>
 16 #include <vtkRenderWindow.h>
 17 #include <vtkRenderWindowInteractor.h>
 18 #include <vtkProperty.h>
 19  
 20 int main()
 21 {
 22     vtkSmartPointer<vtkPolyDataReader> reader =
 23         vtkSmartPointer<vtkPolyDataReader>::New();
 24     reader->SetFileName("fran_cut.vtk");
 25     reader->Update();
 26  
 27     vtkSmartPointer<vtkPolyData> points =
 28         vtkSmartPointer<vtkPolyData>::New();
 29     points->SetPoints(reader->GetOutput()->GetPoints()); //获得网格模型中的几何数据：点集
 30  
 31     vtkSmartPointer<vtkSurfaceReconstructionFilter> surf =
 32         vtkSmartPointer<vtkSurfaceReconstructionFilter>::New();
 33     surf->SetInputData(points);
 34     surf->SetNeighborhoodSize(20);
 35     surf->SetSampleSpacing(0.005);
 36     surf->Update();
 37  
 38     vtkSmartPointer<vtkContourFilter> contour =
 39         vtkSmartPointer<vtkContourFilter>::New();
 40     contour->SetInputConnection(surf->GetOutputPort());
 41     contour->SetValue(0, 0.0);
 42     contour->Update();
 43     //
 44     vtkSmartPointer <vtkVertexGlyphFilter> vertexGlyphFilter =
 45         vtkSmartPointer<vtkVertexGlyphFilter>::New();
 46     vertexGlyphFilter->AddInputData(points);
 47     vertexGlyphFilter->Update();
 48     vtkSmartPointer<vtkPolyDataMapper> pointMapper =
 49         vtkSmartPointer<vtkPolyDataMapper>::New();
 50     pointMapper->SetInputData(vertexGlyphFilter->GetOutput());
 51     pointMapper->ScalarVisibilityOff();
 52  
 53     vtkSmartPointer<vtkActor> pointActor =
 54         vtkSmartPointer<vtkActor>::New();
 55     pointActor->SetMapper(pointMapper);
 56     pointActor->GetProperty()->SetColor(1, 0, 0);
 57     pointActor->GetProperty()->SetPointSize(4);
 58  
 59     vtkSmartPointer<vtkPolyDataMapper> contourMapper =
 60         vtkSmartPointer<vtkPolyDataMapper>::New();
 61     contourMapper->SetInputData(contour->GetOutput());
 62     vtkSmartPointer<vtkActor> contourActor =
 63         vtkSmartPointer<vtkActor>::New();
 64     contourActor->SetMapper(contourMapper);
 65     ///
 66     double pointView[4] = { 0, 0, 0.5, 1 };
 67     double contourView[4] = { 0.5, 0, 1, 1 };
 68  
 69     vtkSmartPointer<vtkRenderer> pointRender =
 70         vtkSmartPointer<vtkRenderer>::New();
 71     pointRender->AddActor(pointActor);
 72     pointRender->SetViewport(pointView);
 73     pointRender->SetBackground(1, 1, 1);
 74  
 75     vtkSmartPointer<vtkRenderer> contourRender =
 76         vtkSmartPointer<vtkRenderer>::New();
 77     contourRender->AddActor(contourActor);
 78     contourRender->SetViewport(contourView);
 79     contourRender->SetBackground(0, 1, 0);
 80  
 81     pointRender->GetActiveCamera()->SetPosition(0, -1, 0);
 82     pointRender->GetActiveCamera()->SetFocalPoint(0, 0, 0);
 83     pointRender->GetActiveCamera()->SetViewUp(0,0,1);
 84     pointRender->GetActiveCamera()->Azimuth(30);
 85     pointRender->GetActiveCamera()->Elevation(30);
 86     pointRender->ResetCamera();
 87     contourRender->SetActiveCamera(pointRender->GetActiveCamera());
 88  
 89     vtkSmartPointer<vtkRenderWindow> rw =
 90         vtkSmartPointer<vtkRenderWindow>::New();
 91     rw->AddRenderer(pointRender);
 92     rw->AddRenderer(contourRender);
 93     rw->SetSize(640, 320);
 94     rw->SetWindowName("3D Surface Reconstruction ");
 95     rw->Render();
 96  
 97     vtkSmartPointer<vtkRenderWindowInteractor> rwi =
 98         vtkSmartPointer<vtkRenderWindowInteractor>::New();
 99     rwi->SetRenderWindow(rw);
100     rwi->Initialize();
101     rwi->Start();
102  
103     return 0;
104 }