A single ROS 2 (Humble) package bundling three utilities:

• pointcloud_to_ply — Capture a point cloud from a topic and store it in .ply or .obj format
• ply_to_xyz_transframer — Transform a .ply file expressed in one frame of reference to a .xyz file expressed in another
• xyz_to_ply_transframer — Transform a .xyz file expressed in one frame of reference to a .ply file expressed in another

cd ~/ros2_ws/src
git clone -b humble-devel https://github.com/li9i/ply-utils.git
cd ~/ros2_ws
rosdep install --from-paths src -y --ignore-src
colcon build --packages-select ply_utils

pointcloud_to_ply additionally requires Open3D, which has no rosdep key:

pip3 install open3d

ros2 launch ply_utils pointcloud_to_ply.launch.xml
ros2 launch ply_utils ply_to_xyz_transframer.launch.xml
ros2 launch ply_utils xyz_to_ply_transframer.launch.xml