7.15-ROS可視化工具-標記

ROS標記工具

ROS標記工具
參考
前言
visuallization_msgs/markers
Sending Basic Shapes to RViz
基本原理
關鍵代碼
Sending Points and lines
Interactive Marker
基本原理
Simple Interactive Marker Server
Basic Control
按鈕
Context Menu
多客戶端單服務器交互
為RViz寫插件
使用QT和librviz進行窗口程序設計

TOC

參考

visualization_msgs
Tutorials
RViz Turorials
RViz User Guid

前言

• 顧名思義，標記工具就是在數據可視化的基礎上加上用戶自定義標記，用來強調某種特征或者添加用戶自己想加上的東西
• visualization stack 現在已經包含到RViz中，但是我們主要還是要學習這個包集中的東西

visuallization_msgs/markers

Sending Basic Shapes to RViz

基本原理

• 注冊一個visualization::marker消息，定義好，然后發出去，RViz在收到后在指定位置顯示特定形狀

關鍵代碼

• package.xml

catkin_create_pkg using_markers roscpp visualization_msgs

• CMakeList.txt

add_executable(basic_shapes src/basic_shapes.cpp)
target_link_libraries(basic_shapes ${catkin_LIBRARIES})

• .cpp

#include <visualization_msgs/Marker.h>
ros::Publisher marker_pub = n.advertise<visualization_msgs::Marker>("visualization_marker", 1);
uint32_t shape = visualization_msgs::Marker::CUBE;
    visualization_msgs::Marker marker;
// Set the frame ID and timestamp.  See the TF tutorials for information on these.
marker.header.frame_id = "/my_frame";
marker.header.stamp = ros::Time::now();
// Set the namespace and id for this marker.  This serves to create a unique ID
// Any marker sent with the same namespace and id will overwrite the old one
marker.ns = "basic_shapes";
marker.id = 0;
// Set the marker type.  Initially this is CUBE, and cycles between that and SPHERE, ARROW, and CYLINDER
marker.type = shape;
// Set the marker action.  Options are ADD, DELETE, and new in ROS Indigo: 3 (DELETEALL)
marker.action = visualization_msgs::Marker::ADD;

// Set the pose of the marker.  This is a full 6DOF pose relative to the frame/time specified in the header
marker.pose.position.x = 0;
marker.pose.position.y = 0;
marker.pose.position.z = 0;
marker.pose.orientation.x = 0.0;
marker.pose.orientation.y = 0.0;
marker.pose.orientation.z = 0.0;
marker.pose.orientation.w = 1.0;
// Set the scale of the marker -- 1x1x1 here means 1m on a side
marker.scale.x = 1.0;
marker.scale.y = 1.0;
marker.scale.z = 1.0;
// Set the color -- be sure to set alpha to something non-zero!
marker.color.r = 0.0f;
marker.color.g = 1.0f;
marker.color.b = 0.0f;
marker.color.a = 1.0;
marker.lifetime = ros::Duration();
// Publish the marker
while (marker_pub.getNumSubscribers() < 1)
{
    if (!ros::ok())
    {
        return 0;
    }
    ROS_WARN_ONCE("Please create a subscriber to the marker");
    sleep(1);
}
marker_pub.publish(marker);

Sending Points and lines

• 本質同發送基本形狀，都是定義一個消息，然后發送即可，只是點和線可能是數組數據結構，定義起來麻煩一點

Interactive Marker

基本原理

• 不僅是將特定形狀顯示在RViz中，而且用戶可以使用鼠標和上下文菜單進行交互，從而實現更復雜的任務
• 依然是由消息類型來定義，visualization_msgs/InteractiveMarker，這個消息包含一個上下文菜單，多個控件（visualization_msgs/InteractiveMarkerControl消息類型表示）。這些控件用來定義交互式標記的各個部分，每一部分都有不同功能。
• 要使用交互式標記，需要在節點中實例化一個InteractiveMarkerServer對象，作為與RViz聯系的代理服務器，RViz作為客戶端向節點發送不同的消息通知，以此來產生交互。
• 相關的消息類型有
  • visualization_msgs/InteractiveMarker
  • visualization_msgs/InteractiveMarkerControl
  • visualization_msgs/InteractiveMarkerFeedback
    此外還有MenuHandler
• 幫助文檔

Simple Interactive Marker Server

• 關鍵思想
  • InteractiveMarker-->control-->Marker，標記包含控件，類間是組合關系，均是一對多。
  • 咦？為什么同時有將control賦給marker的屬性和將marker賦給control的屬性？原來如此
  • Server給RViz發送Update消息，RViz給Server發送Feedback，Server處定義對Feedback的響應函數
• 關鍵代碼

#include <ros/ros.h>

#include <interactive_markers/interactive_marker_server.h>

void processFeedback(
    const visualization_msgs::InteractiveMarkerFeedbackConstPtr &feedback )
{
  ROS_INFO_STREAM( feedback->marker_name << " is now at "
      << feedback->pose.position.x << ", " << feedback->pose.position.y
      << ", " << feedback->pose.position.z );
}

int main(int argc, char** argv)
{
  ros::init(argc, argv, "simple_marker");

  // create an interactive marker server on the topic namespace simple_marker
  interactive_markers::InteractiveMarkerServer server("simple_marker");

  // create an interactive marker for our server
  visualization_msgs::InteractiveMarker int_marker;
  int_marker.header.frame_id = "base_link";
  int_marker.header.stamp=ros::Time::now();
  int_marker.name = "my_marker";
  int_marker.description = "Simple 1-DOF Control";

  // create a grey box marker
  visualization_msgs::Marker box_marker;
  box_marker.type = visualization_msgs::Marker::CUBE;
  box_marker.scale.x = 0.45;
  box_marker.scale.y = 0.45;
  box_marker.scale.z = 0.45;
  box_marker.color.r = 0.5;
  box_marker.color.g = 0.5;
  box_marker.color.b = 0.5;
  box_marker.color.a = 1.0;

  // create a non-interactive control which contains the box
  visualization_msgs::InteractiveMarkerControl box_control;
  box_control.always_visible = true;
  box_control.markers.push_back( box_marker );

  // add the control to the interactive marker
  int_marker.controls.push_back( box_control );

  // create a control which will move the box
  // this control does not contain any markers,
  // which will cause RViz to insert two arrows
  visualization_msgs::InteractiveMarkerControl rotate_control;
  rotate_control.name = "move_x";
  rotate_control.interaction_mode =
      visualization_msgs::InteractiveMarkerControl::MOVE_AXIS;

  // add the control to the interactive marker
  int_marker.controls.push_back(rotate_control);

  // add the interactive marker to our collection &
  // tell the server to call processFeedback() when feedback arrives for it
  server.insert(int_marker, &processFeedback);

  // 'commit' changes and send to all clients
  server.applyChanges();

  // start the ROS main loop
  ros::spin();
}

Basic Control

• 告訴你怎樣制作一個6-DOF的控件（包括在控制時控件和場景一起移動的，和控件固定的）
• 關鍵代碼

按鈕

• 基本思路
  • 就像菜單欄中的按鈕一樣
  • 默認是響應鼠標左鍵
• 關鍵代碼

https://raw.githubusercontent.com/ros-visualization/visualization_tutorials/groovy-devel/interactive_marker_tutorials/src/basic_controls.cpp

Context Menu

• 基本思路
  • 將靜態菜單附着到一個交互式標記（Interactive Marker）上

多客戶端單服務器交互

• 意義
  • 可以同時有多個RViz客戶端控制一個或多個交互式控件Marker
  • 這個例子實現了一個簡易乒乓球游戲
  • 以后再學吧。

為RViz寫插件

• 感覺沒有學這個的需求啊。。。

使用QT和librviz進行窗口程序設計

• 這個相當於是使用QT對RViz進行簡單的二次開發，感覺應該要學，既不需要深度了解QT，又可以編出像樣的界面，哈哈！