使用rviz2中的PointCloud打点Status：Error

[2235674044]

原码如下：

#include "rclcpp/rclcpp.hpp"
#include "std_msgs/msg/string.hpp"
#include "std_msgs/msg/u_int32.hpp"
#include "sensor_msgs/point_cloud_conversion.hpp"
#include "sensor_msgs/point_cloud2_iterator.hpp"
#include <chrono>
#include <memory>

using namespace std::chrono_literals;
using namespace geometry_msgs;

using std::placeholders::_1;
using std::placeholders::_2;

/*
    创建一个类节点，名字叫做SingleDogNode,继承自Node.
*/
class SingleDogNode : public rclcpp::Node
{

public:
    // 构造函数,有一个参数为节点名称
    SingleDogNode(std::string name) : Node(name)
    {
        publisher_ = this->create_publisher<sensor_msgs::msg::PointCloud>("multi_points", 10);
        timer_ = this->create_wall_timer(1s, std::bind(&SingleDogNode::timer_callback, this));
    }

private:
    rclcpp::TimerBase::SharedPtr timer_;
    sensor_msgs::msg::PointCloud point_data;
    rclcpp::Publisher<sensor_msgs::msg::PointCloud>::SharedPtr publisher_;
    char count_x = 0;
    char count_y = 0;
    void timer_callback()
    {
        geometry_msgs::msg::Point32 p;
        p.x = count_x;
        p.y = count_y;
        p.z = 0;
        point_data.points.push_back(p);
        publisher_->publish(point_data);
        count_x++;
        count_y++;
    }
};

int main(int argc, char **argv)
{
    rclcpp::init(argc, argv);
    /*产生一个Wang2的节点*/
    auto node = std::make_shared<SingleDogNode>("li4");
    /* 运行节点，并检测退出信号*/
    rclcpp::spin(node);
    rclcpp::shutdown();
    return 0;
}

运行结果：

工程目录

请问是哪一块出问题了

[小鱼]

@2235674044 看错误很简单，fixedframe为map的时候tf变换不到这个坐标系，所以你应该重新选一个fixedframe即可。

[2235674044]

@小鱼 你好 这个怎么重新选一个fixedframe呢

[小鱼]

@2235674044 在 使用rviz2中的PointCloud打点Status：Error 中说：

point_data

在你的程序，这个数据里应该可以给frame_id进行赋值，赋一个字符串，接着你在修改rviz2中第一栏frame_id保持和程序中的相同即可

[2235674044]

@小鱼 请问ros2中怎么给话题的frame_id赋值呢

[小鱼]

@2235674044 look

fishros@fishros-MS-7D42:~$ ros2 interface show sensor_msgs/msg/PointCloud
## THIS MESSAGE IS DEPRECATED AS OF FOXY
## Please use sensor_msgs/PointCloud2

# This message holds a collection of 3d points, plus optional additional
# information about each point.

# Time of sensor data acquisition, coordinate frame ID.
std_msgs/Header header
	builtin_interfaces/Time stamp
		int32 sec
		uint32 nanosec
	string frame_id

# Array of 3d points. Each Point32 should be interpreted as a 3d point
# in the frame given in the header.
geometry_msgs/Point32[] points
	#
	#
	float32 x
	float32 y
	float32 z

# Each channel should have the same number of elements as points array,
# and the data in each channel should correspond 1:1 with each point.
# Channel names in common practice are listed in ChannelFloat32.msg.
ChannelFloat32[] channels
	#
	string name
	float32[] values

so

    rclcpp::TimerBase::SharedPtr timer_;
    sensor_msgs::msg::PointCloud point_data;
    point_data.header.frame_id = "你的frameid";
    rclcpp::Publisher<sensor_msgs::msg::PointCloud>::SharedPtr publisher_;
    char count_x = 0;
    char count_y = 0;

[2235674044]

@小鱼 解决了 感谢大佬

[小鱼]

@2235674044 基操勿6