How to get values from geometry_msgs/Pose Message (Ros2)?

cecelu · November 30, 2022, 12:49am

Hi,
I have created a connection between Unity and Ros2 via INode ISubscription.
Accessing float, string values works. But now I would like to use Pose. How do I access the nested values in Unity there?

LaurieUnity · December 8, 2022, 8:05pm

You should be able to access its properties like any other property - myPoseMsg.position and myPoseMsg.orientation.
To convert them into Unity coordinates you can write myPoseMsg.position.From().
See RosGeometry docs here:

github.com

Unity-Technologies/ROS-TCP-Connector/blob/main/ROSGeometry.md

# ROSGeometry component

In Unity, the X axis points right, Y up, and Z forward. ROS, on the other hand, supports various coordinate frames: in the most commonly-used one, X points forward, Y left, and Z up. In ROS terminology, this frame is called "FLU" (forward, left, up), whereas the Unity coordinate frame would be "RUF" (right, up, forward).

The ROSGeometry namespace contains code to make it easier to work with these various coordinate frames - letting you be explicit about what coordinates a given value is in at compile time, and managing the conversions for you.

Here's the using declaration for adding ROSGeometry to your namespace:

    using Unity.Robotics.ROSTCPConnector.ROSGeometry;

# Ros Message conversions:

The main ROS position messages (geometry_msgs/Point, geometry_msgs/Point32 and geometry_msgs/Vector3) can be converted to and from Unity Vector3s like this:

	PointMsg ToRosExample(Vector3 position)
	{
		return position.To<FLU>();
	}

	Vector3 ToUnityExample(PointMsg message)

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