pcl虚拟扫描仪的姿势

Question

我想使用PCL虚拟扫描仪获取CAD模型的部分快照。

我通过引用tutorial

#include <pcl/io/vtk_lib_io.h>
#include <vtkPolyDataMapper.h>
#include <pcl/apps/render_views_tesselated_sphere.h>

int
main(int argc, char** argv)
{
    // Load the PLY model from a file.
    vtkSmartPointer<vtkPLYReader> reader = vtkSmartPointer<vtkPLYReader>::New();
    reader->SetFileName(argv[1]);
    reader->Update();

    // VTK is not exactly straightforward...
    vtkSmartPointer < vtkPolyDataMapper > mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
    mapper->SetInputConnection(reader->GetOutputPort());
    mapper->Update();

    vtkSmartPointer<vtkPolyData> object = mapper->GetInput();

    // Virtual scanner object.
    pcl::apps::RenderViewsTesselatedSphere render_views;
    render_views.addModelFromPolyData(object);
    // Pixel width of the rendering window, it directly affects the snapshot file size.
    render_views.setResolution(150);
    // Horizontal FoV of the virtual camera.
    render_views.setViewAngle(57.0f);
    // If true, the resulting clouds of the snapshots will be organized.
    render_views.setGenOrganized(true);
    // How much to subdivide the icosahedron. Increasing this will result in a lot more snapshots.
    render_views.setTesselationLevel(1);
    // If true, the camera will be placed at the vertices of the triangles. If false, at the centers.
    // This will affect the number of snapshots produced (if true, less will be made).
    // True: 42 for level 1, 162 for level 2, 642 for level 3...
    // False: 80 for level 1, 320 for level 2, 1280 for level 3...
    render_views.setUseVertices(true);
    // If true, the entropies (the amount of occlusions) will be computed for each snapshot (optional).
    render_views.setComputeEntropies(true);

    render_views.generateViews();

    // Object for storing the rendered views.
    std::vector<pcl::PointCloud<pcl::PointXYZ>::Ptr> views;
    // Object for storing the poses, as 4x4 transformation matrices.
    std::vector<Eigen::Matrix4f, Eigen::aligned_allocator<Eigen::Matrix4f> > poses;
    // Object for storing the entropies (optional).
    std::vector<float> entropies;
    render_views.getViews(views);
    render_views.getPoses(poses);
    render_views.getEntropies(entropies);
}

正常的快照估计正常工作。但是方向是模棱两可的。

我认为是由于默认视点（0,0,0,1,0,0,0），我想设置视点，但是我应该设置什么值？

我认为render_views.getPoses(poses)中的姿势；可能会有所帮助，但是该姿势也会使我感到困惑，该姿势基于哪个坐标系以及该姿势属于什么坐标系？相机还是物体？

您能给我一些建议吗？非常感谢。