Nanoflann findNeighbors引发段错误

Question

所以我有以下类KdTree：

#include <nanoflann.hpp>
#include <ctime>
#include <cstdlib>
#include <iostream>
#include <memory>
#include <cstdlib>
#include <iostream>

struct PointCloud
{
    struct Point
    {
        double  x,y,z;
    };

    std::vector<Point>  pts;

    inline size_t kdtree_get_point_count() const { return pts.size(); }

    inline double kdtree_get_pt(const size_t idx, const size_t dim) const
    {
        if (dim == 0) return pts[idx].x;
        else if (dim == 1) return pts[idx].y;
        else if (dim == 2) return pts[idx].z;
    }

    template <class BBOX>
    bool kdtree_get_bbox(BBOX& /* bb */) const { return false; }

};

void generatePointCloud(PointCloud &point, const std::vector<std::vector<double>>& given)
{
    point.pts.resize(given.size());
for (size_t i = 0; i < given.size(); ++i) {
    point.pts[i].x = given[i][0];
    point.pts[i].y = given[i][1];
    point.pts[i].z = given[i][2];
}
}

using namespace nanoflann;
using Points = std::vector<std::vector<double>>;

class KdTree {
public:
    KdTree(const Points& points) {
        PointCloud cloud;
        generatePointCloud(cloud, points); // just puts points into cloud format
        index = std::make_shared<my_kd_tree>(3 /*dim*/, cloud, KDTreeSingleIndexAdaptorParams(10 /* max leaf */) );
        index->buildIndex();
    }

    size_t GetNearest(const std::vector<double>& pt) const {
        double query_pt[3] = { pt[0], pt[1], pt[2] };
        const size_t num_results = 1;
        size_t ret_index;
        double out_dist_sqr;
        nanoflann::KNNResultSet<double > resultSet(num_results);
        resultSet.init(&ret_index, &out_dist_sqr );
        index->findNeighbors(resultSet, &query_pt[0], nanoflann::SearchParams(10));
        std::cout << "knnSearch(nn="<<num_results<<"): \n";
        std::cout << "ret_index=" << ret_index << " out_dist_sqr=" << out_dist_sqr << endl;
        return ret_index;
    }

    typedef KDTreeSingleIndexAdaptor<
            L2_Simple_Adaptor<double , PointCloud > ,
            PointCloud,
            3 /* dim */
    > my_kd_tree;
    std::shared_ptr<my_kd_tree> index = nullptr;
};

问题是以下代码引发了段错误：

int main()
{
    srand(static_cast<unsigned int>(time(nullptr)));
    Points points{{1, 5, 8}, {3, 3, 3}, {1, 1, 0}};
    KdTree tree(points);
    tree.GetNearest({1, 1, 1});
    return 0;
}

但是如果我将GetNearest代码放入构造函数中（以便我构造索引并在构造函数本身中找到pt的邻居，或者只在main中编写构造函数和GetNearest代码，则一切正常。] >

我是nanoflann的新手，无法弄清楚出了什么问题。感谢您的提前帮助！

所以我有以下类KdTree：#include #include #include #include #include #include ＃...

Answer 1

我不得不深入研究源nanoflann.hpp，以发现KDTreeSingleIndexAdaptor的构造函数的第二个参数（您的cloud构造函数中的KdTree）通过引用传递，而stored