1. kdtree近邻搜索
#include <pcl/point_cloud.h> //定义PointCloud格式点云
#include <pcl/kdtree/kdtree_flann.h> //KdTreeFLANN是一种KD-tree结构,使用FLANN( 快速最近邻逼近搜索函数库)实现高效搜索
//【1】定义kdtree对象
pcl::KdTreeFLANN<pcl::PointXYZ> kdtree;
//将点云集输入到kdtree中
kdtree.setInputCloud (cloud);
//【2】设置搜索目标点
pcl::PointXYZ searchPoint;
searchPoint.x=1024.0f* rand () / (RAND_MAX +1.0f);
searchPoint.y=1024.0f* rand () / (RAND_MAX +1.0f);
searchPoint.z=1024.0f* rand () / (RAND_MAX +1.0f);
//【3】K近邻搜索
int K =10; //搜索近邻个数
std::vector<int>pointIdxNKNSearch(K); //存放近邻点在原点云集的索引
std::vector<float>pointNKNSquaredDistance(K); //对应近邻的平方距离
std::cout<<"K nearest neighbor search at ("<<searchPoint.x
<<" "<<searchPoint.y
<<" "<<searchPoint.z
<<") with K="<< K <<std::endl;
// 开始kdtree K近邻搜索
if ( kdtree.nearestKSearch (searchPoint, K, pointIdxNKNSearch, pointNKNSquaredDistance) >0 )
{
for (size_t i=0; i<pointIdxNKNSearch.size (); ++i)
std::cout<<" "<< cloud->points[ pointIdxNKNSearch[i] ].x
<<" "<< cloud->points[pointIdxNKNSearch[i] ].y
<<" "<< cloud->points[pointIdxNKNSearch[i] ].z
<<" (squared distance: "<<pointNKNSquaredDistance[i] <<")"<<std::endl;
}
//【4】或者在半径r内搜索
float radius =256.0f* rand () / (RAND_MAX +1.0f); //设置搜索半径
std::vector<int> pointIdxRadiusSear