Frames in rviz

1. Install the ROS package agni-tf-tools

sudo apt install ros-noetic-agni-tf-tools

2. Source your ROS environment, and start roscore as well as rviz

source /opt/ros/noetic/setup.bash
roscore &
rosrun rviz rviz

3. Add new displays, namely TF and Static Transform Publisher

Using several transform publishers, build up a transformation tree like this:

world
 ↳ T1 → R1
 ↳ R2 → T2

where translations (T) are 0.5m along the y-axis, and rotations (R) are -90° about the z-axis (see image).

4. Using the TF display, readout the following relative transforms

• world → R1
• R1 → world
• R1 → T2

To this end, define rviz's fixed frame to the parent frame and readout the corresponding transformation from the child frame in TF display's frames list.