在PCL库中插入pcl::octree::OctreePointCloudSearch<pcl::PointXYZ>索引

Question

我正在尝试使用pcl::octree::OctreePointCloudSearch<pcl::PointXYZ> octree对点云进行分区&执行一些操作。

在该方法中，它提供了一个称为

setInputCloud(const PointCloudConstPtr &cloud_arg, IndicesConstPtr &indices_arg = IndicesConstPtr ())

在文档中，解释如下所示。

*\brief Provide a pointer to the input data set.
     * \param[in] cloud_arg the const boost shared pointer to a PointCloud message
     * \param[in] indices_arg the point indices subset that is to be used from \a cloud - if 0 the whole point cloud is used

此外，

// public typedefs
typedef boost::shared_ptr<const std::vector<int> > IndicesConstPtr;
typedef pcl::PointCloud<PointT> PointCloud;
typedef boost::shared_ptr<const PointCloud> PointCloudConstPtr;

我已经做的是，

pcl::PointCloud<pcl::PointXYZ>::Ptr inputCloud (new pcl::PointCloud<pcl::PointXYZ> ());
pcl::PointIndices::Ptr cloudIndices(new pcl::PointIndices());
pcl::PointIndices::Ptr selectedIndices(new pcl::PointIndices());

/* some code to fill inputCloud and cloudIndices & selectedIndices
(selectedIndices is contains only chosen indices set from all cloudIndices) */

float resolution = 0.1;
pcl::octree::OctreePointCloudSearch<pcl::PointXYZ> octree(resolution);
octree.setInputCloud(inputCloud);
octree.addPointsFromInputCloud();

这个很好用。但是，在不使用selectedIndices创建新的点云的情况下，我需要使用现有的inputCloud并对函数使用selectedIndices。

我知道octree.setInputCloud(inputCloud, selectedIndices);函数不起作用。它回来了

error: cannot convert ‘pcl::PointIndices::Ptr’ {aka ‘std::shared_ptr<pcl::PointIndices>’} to ‘const IndicesConstPtr&’ {aka ‘const std::shared_ptr<const std::vector<int> >&’}
  169 |     octree.setInputCloud (inputCloud,selectedIndices);
      |                                             ^~~~~~~~~~~~~~~~~~~~~~
      |                                             |
      |                                             pcl::PointIndices::Ptr {aka std::shared_ptr<pcl::PointIndices>}

我需要转换std::shared_ptr<pcl::PointIndices>const to std::shared_ptr<const std::vector<int> >&吗？我该怎么做？

Answer 1

找到了解决上述问题的方法。

PCL函数

 setInputCloud(const PointCloudConstPtr &cloud_arg, IndicesConstPtr &indices_arg = IndicesConstPtr ())

接受索引，但必须将其转换为pcl::IndicesPtr类型。

所以，我的解决办法是，

pcl::IndicesPtr indicesTemp(new std::vector<int>());
std::copy(selectedIndices->indices.begin(), selectedIndices->indices.end(), std::back_inserter(*indicesTemp));

float resolution = 0.1;
pcl::octree::OctreePointCloudSearch<pcl::PointXYZ> octree(resolution);
octree.setInputCloud(inputCloud,indicesTemp);
octree.addPointsFromInputCloud();

结果与预期相符。