#20015·o3de

Bug Report-Support inertia tensor import from URDF for ArticulationLink to disable auto-calculation

Author: welber-zhangCreated Aug 17, 2026Updated Aug 25, 2026
Labelskind/bugneeds-priorityneeds-triagesig/simulation

Describe the bug When importing URDF files, the ArticulationLink component does not read the Inertia Tensor data from the tag in the URDF. This causes the articulation chain to use default auto-calculated inertia values in physics simulation instead of the precise inertia values defined in the URDF file. This issue results in significant discrepancies between O3DE's articulation chain simulation results and other physics simulation engines like Isaac Sim, affecting simulation accuracy and cross-platform consistency. Assets required A URDF file with complete definitions, including mass, center of mass offset, and inertia tensor configuration. Steps to reproduce Steps to reproduce the behavior:

  1. Prepare a URDF file with antag containing explicitly defined inertia tensor values
  2. Import the URDF file into the O3DE engine using ROS2RobotImporter
  3. Inspect the generated ArticulationLink component configuration in the editor
  4. Check whether them_inertiaTensorfield is correctly read from the URDF
  5. Run physics simulation and compare O3DE's articulation chain simulation results with Isaac Sim's simulation results Expected behavior The ArticulationLink component should correctly read the inertia tensor data from the URDF's tag, set m_inertiaTensor to the values defined in the URDF, and set m_computeInertiaTensor to false to disable auto-calculation. The articulation chain simulation results should be consistent with other physics simulation engines like Isaac Sim. Actual behavior The ArticulationLink component does not read the inertia tensor data from the URDF. The m_inertiaTensor uses default values or is auto-calculated by the system, causing the articulation chain simulation behavior to deviate from the physical properties defined in the URDF, resulting in significant discrepancies compared to Isaac Sim's simulation results. Screenshots/Video None Found in Branch development Commit ID from o3de/o3de Repository 855799355475acaa701408fd76cf8fadec5d92a4 Desktop/Device (please complete the following information): ● Device: PC ● OS: Ubuntu ● CPU: Intel/AMD ● GPU: NVIDIA/AMD ● Memory: 16GB+

I Plan to submit a PR to fix this