Add info on installing rerun-urdf-loader

Author: pierre-rouanet

examples/rerun_viewer.py

@@ -3,6 +3,9 @@
 Open a wav and push samples to the speaker. This is a toy example, in real
 conditions output from a microphone or a text-to-speech engine would be
  pushed to the speaker instead.
+
+It requires the 'rerun-loader-urdf' package to be installed. It's not on PyPI,
+so you need to install it from the GitHub repository: pip install git+https://github.com/rerun-io/rerun-loader-python-example-urdf.git
 """
 
 import logging

src/reachy_mini/utils/rerun.py

@@ -18,7 +18,15 @@
 import numpy as np
 import requests
 import rerun as rr
-from rerun_loader_urdf import URDFLogger
+
+try:
+    from rerun_loader_urdf import URDFLogger
+except ImportError:
+    raise ImportError(
+        "The 'rerun-loader-urdf' package is required for this module. "
+        "Please install it from the GitHub repository: "
+        "pip install git+https://github.com/rerun-io/rerun-loader-python-example-urdf.git"
+    )
 from urdf_parser_py import urdf
 
 from reachy_mini.kinematics.placo_kinematics import PlacoKinematics