Known Issues and Limitations

Known Issues and Limitations#

This section outlines known issues and current limitations in URBAN-SIM, including hardware requirements, missing dependencies, upcoming asset releases, etc.

Module Not Found Error#

If you meet the error ModuleNotFoundError: No module named 'xxx', ensure that the conda environment is activated and use

source _isaac_sim/setup_conda_env.sh to set up the conda environment.

CUDA & GLIBCXX Incompatibility#

URBAN-SIM relies on many libraries and systems like NVIDIA Isaac Sim, which requires supports of libstdc++ for successful runtime. On some systems, especially with custom Anaconda installations, the following error may occur:

ImportError: ... libstdc++.so.6: version `GLIBCXX_3.4.32' not found

Solution: Ensure your environment uses a system-level libstdc++.so.6 with GLIBCXX_3.4.32+. You can verify this with:

strings $(g++ -print-file-name=libstdc++.so.6) | grep GLIBCXX

If you can find GLIBCXX_3.4.32 or higher in the output, your system is compatible. At this time, if you are using a custom Anaconda installation, you may need to install the system-level libstdc++ package or replace the link of libstdc++.so.6 in Anaconda with the system version.

A100 GPU Compatibility#

Isaac Sim currently does not support running on NVIDIA A100 GPUs due to limitations in the OptiX and PhysX backends. Attempting to launch on an A100 may result in failure to create Vulkan/OpenGL contexts or invalid CUDA device errors.

We recommend using RTX 30xx / 40xx / 50xx consumer cards or supported workstation GPUs.

Asset Availability#

Some assets in URBAN-SIM scenarios are under construction or being curated for release. More specifically:

  • Static objects: Static objects are currently partial; full set with more than 1.5W well-annotated assets will be released progressively.

  • Pedestrians: We use pedestrian assets from Synbody project. To reduce space and streamline runtime loading, only a subset of Synbody models is currently included in URBAN-SIM. We will release the code to process and load the Synbody asset and convert them to .usd format in the future. Currently, you can convert Synbody assets to .usd format using the Isaacsim GUI.

Please stay tuned via our repo or project page for updates.