Side silhouettes derived from zeronce-hardware/quad/figures/quadruped_comparison_side.svg.
Unitree Go2 model: Unitree Robotics, BSD-3-Clause, see unitree_go2-LICENSE.txt.
Spot model: Clearpath Robotics, BSD-3-Clause, see boston_dynamics_spot-LICENSE.txt.
Original model distribution: https://github.com/google-deepmind/mujoco_menagerie
Go2 and Spot outline envelopes normalized to published standing dimensions.
Quad silhouette: current Zeronce modular URDF snapshot b800b749ad8e, orthographic side projection of original CAD triangles.