Error when trying to read Point Cloud Data

[Ushtarador]

Checklist

• [X] I've read the contribution guidelines.
• [X] I've searched other issues and no duplicate issues were found.

Description

Hey all,

I got another problem, and it would be great to get some input on this. I'd like to publish the point cloud data in a ROS1 message, so unfortunately I can't take advantage of the existing ROS2 implementation (unless I'm missing something?).

This is the code I wrote:

public class RGLLidarROS_PointCloudPublisher : MonoBehaviour
    {        
        private LidarSensor lidarSensor;
        private RGLNodeSequence rglSubgraphUnity2Ros1;
        // Start is called before the first frame update
        void Start()
        {
            lidarSensor = GetComponent<LidarSensor>();

            rglSubgraphUnity2Ros1 = new RGLNodeSequence().AddNodePointsTransform("UNITY_TO_ROS", Matrix4x4.identity);
            lidarSensor.ConnectToLidarFrame(rglSubgraphUnity2Ros1);

            lidarSensor.onNewData += publishPointCloudMessage;                                    
        }

        private void publishPointCloudMessage()
        {
            Vector3[] pointCloud = new Vector3[0];
            rglSubgraphUnity2Ros1.GetResultData<Vector3>(ref pointCloud);
            //write pointCloud into a ROS1 message
        }
    }

Unfortunately, I'm getting this error when calling GetResultData:

If anyone could point me in the right direction on how to directly extract the point cloud data that would be great!

[msz-rai]

Hey @Ushtarador Thank you for the message.

Your code is almost correct. One thing that has been missed is setting the output node to the RGLNodeSequence. It it required to inform RGL what fields are expected to produce them. An single field can be requested (with NodePointsYield) or multiple fields that will be converted into binary format (with NodePointsFormat).

In your case, if you want to get XYZ data, you need to add AddNodePointsYield as follows: rglSubgraphUnity2Ros1 = new RGLNodeSequence().AddNodePointsTransform("UNITY_TO_ROS", Matrix4x4.identity); rglSubgraphUnity2Ros1.AddNodePointsYield("GET_XYZ", RGLField.XYZ_F32);

Please let me know, if it helped you.

[Ushtarador]

Hey @msz-rai, Ah I've missed that in the other code, adding the yield node worked, thanks a lot!

Cheers, Christoph