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ROS–Unity Integration: UnityService

Create a simple Unity scene which runs a Service in Unity that takes a request with a GameObject's name and responds with the GameObject's pose (position and orientation) in the ROS coordinate system.

Setting Up

Follow the ROS–Unity Demo Setup guide if you haven't already done so.

Create Unity Service

Create a new C# script and name it RosUnityServiceExample.cs
Paste the following code into RosUnityServiceExample.cs
- (Alternatively, you can drag the script file into Unity from tutorials/ros_unity_integration/unity_scripts).

using RosMessageTypes.UnityRoboticsDemo;
using UnityEngine;
using Unity.Robotics.ROSTCPConnector;
using Unity.Robotics.ROSTCPConnector.ROSGeometry;

/// <summary>
/// Example demonstration of implementing a UnityService that receives a Request message from another ROS node and sends a Response back
/// </summary>
public class RosUnityServiceExample : MonoBehaviour
{
    [SerializeField]
    string m_ServiceName = "obj_pose_srv";

    void Start()
    {
        // register the service with ROS
        ROSConnection.instance.ImplementService<ObjectPoseServiceRequest>(m_ServiceName, GetObjectPose);
    }

    /// <summary>
    ///  Callback to respond to the request
    /// </summary>
    /// <param name="request">service request containing the object name</param>
    /// <returns>service response containing the object pose (or 0 if object not found)</returns>
    private ObjectPoseServiceResponse GetObjectPose(ObjectPoseServiceRequest request)
    {
        // process the service request
        Debug.Log("Received request for object: " + request.object_name);

        // prepare a response
        ObjectPoseServiceResponse objectPoseResponse = new ObjectPoseServiceResponse();
        // Find a game object with the requested name
        GameObject gameObject = GameObject.Find(request.object_name);
        if (gameObject)
        {
            // Fill-in the response with the object pose converted from Unity coordinate to ROS coordinate system
            objectPoseResponse.object_pose.position = gameObject.transform.position.To<FLU>();
            objectPoseResponse.object_pose.orientation = gameObject.transform.rotation.To<FLU>();
        }

        return objectPoseResponse;
    }
}

Create an empty GameObject and name it UnityService.
Attach the RosUnityServiceExample script to the UnityService GameObject.
Pressing play in the Editor should start running as a ROS node, waiting to accept ObjectPose requests. Once a connection to ROS has been established, a message will be printed on the ROS terminal similar to Connection from 172.17.0.1.

Start the Client

To test our new service is working, let's call it using the built-in ROS service command.

a) In ROS1, run the following command in your ROS terminal:

rosservice call /obj_pose_srv Cube

In your Unity console you should see the log message Received request for object: Cube, and in your terminal it will report the object's position, like this:

object_pose:
 position:
   x: 0.0
   y: -1.0
   z: 0.20000000298023224
 orientation:
   x: 0.0
   y: -0.0
   z: 0.0
   w: -1.0

b) If you're using ROS2, the command is:

ros2 service call obj_pose_srv unity_robotics_demo_msgs/ObjectPoseService "{object_name: Cube}"


 And the output will look like this:

 ```bash
 requester: making request: unity_robotics_demo_msgs.srv.ObjectPoseService_Request(object_name='Cube')
 response:
 unity_robotics_demo_msgs.srv.ObjectPoseService_Response(object_pose=geometry_msgs.msg.Pose(position=geometry_msgs.msg.Point(x=0.0, y=-0.0, z=0.0), orientation=geometry_msgs.msg.Quaternion(x=-0.558996319770813, y=-0.3232670724391937, z=-0.6114855408668518, w=-0.4572822153568268)))

Continue to the ROS–Unity Integration Service Call.

4.1 KiB 原始文件 永久链接 文件历史

ROS–Unity Integration: UnityService

Setting Up

Create Unity Service

Start the Client

4.1 KiB

原始文件永久链接文件历史