pixi.lockis pinned tohttps://mirrors.zju.edu.cn, which may be slow or unreachable outside the authors' network.piximay inherit cache paths from your shell, and those paths are often not writable on shared systems.- Several dependencies are compiled from source against the exact PyTorch/CUDA environment.
Use the steps below from the repository root.
Pick cache directories under your home directory or another location you own:
export HUGSIM_CACHE_ROOT="${HOME}/.cache/hugsim"
export PIXI_HOME="${HUGSIM_CACHE_ROOT}/pixi"
export PIP_CACHE_DIR="${HUGSIM_CACHE_ROOT}/pip"
export UV_CACHE_DIR="${HUGSIM_CACHE_ROOT}/uv"
mkdir -p "${PIXI_HOME}" "${PIP_CACHE_DIR}" "${UV_CACHE_DIR}"If your shell startup files already export PIXI_HOME, PIP_CACHE_DIR, or UV_CACHE_DIR, override them before every install, or update your shell config to point at writable paths.
The training and reconstruction code depends on CUDA-enabled PyTorch packages:
nvidia-smi
nvcc --versionRecommended minimum checks:
nvidia-smishould work and show a GPU.nvccshould exist if you need to build CUDA extensions such assimple-knn,tinycudann, andapex.
If nvidia-smi fails, fix the server GPU/driver setup first. HUGSIM will not install cleanly without a working CUDA environment.
If you already have a partial .pixi environment from a failed install, remove only the repo-local environment directory:
rm -rf .pixiDo not remove your global cache directories unless you want to force all packages to be downloaded again.
The repository lockfile currently references the ZJU mirror. On a US campus server, the simplest fix is usually:
mv pixi.lock pixi.lock.zjuThat forces pixi to resolve packages from the manifest instead of reusing the pinned mirror URLs. If your network can reach the ZJU mirror reliably, you can keep the lockfile.
The authors intentionally split installation into a binary-first pass and a source-build pass.
Edit pixi.toml and temporarily comment out the entries under # install from source code:
hugsim-envsimple-knngsplatflow-vis-torchunidepthtrajdatatinycudannkitti360Scriptssimple-waymo-open-dataset-readerpytorch3dnuscenes-devkit
Keep moviepy enabled. It is not a source-build package.
Then install:
pixi installUncomment the source-build dependencies again, then run:
pixi installInverseForm depends on NVIDIA Apex:
pixi run install-apexThis clones apex into data/InverseForm/apex and builds CUDA/C++ extensions against the active pixi environment.
Run a small import check:
pixi run python -c "import torch, open3d, roma, gymnasium; print(torch.__version__)"
LD_LIBRARY_PATH="$PWD/.pixi/envs/default/lib/python3.11/site-packages/torch/lib:$PWD/.pixi/envs/default/lib${LD_LIBRARY_PATH:+:$LD_LIBRARY_PATH}" \
pixi run python -c "from simple_knn._C import distCUDA2; import tinycudann as tcnn; from gsplat.rendering import rasterization; print('cuda extensions ok')"If the second command fails, the environment usually has one of these problems:
- PyTorch and CUDA toolkit versions do not match
nvccis missing- the install was attempted before
nvidia-smiworked - the source-built packages were installed before the base torch environment was ready
LD_LIBRARY_PATHdoes not include PyTorch's shared libraries on your server runtime
For convenience, you can source scripts/activate_hugsim.sh, which sets writable cache paths and the required LD_LIBRARY_PATH for this repo-local environment.
Data preparation also needs:
- InverseForm checkpoints placed where the
data/InverseForm/infer_*.shscripts expect them - dataset downloads for KITTI-360, Waymo, nuScenes, or PandaSet
See data/README.md for the data pipeline details.
Closed-loop simulation is not self-contained in this repo. Before running closed_loop.py, install one of the external AD clients the README mentions:
- UniAD_SIM
- VAD_SIM
- NAVSIM
Those client environments can be separate from HUGSIM's pixi environment.
pixi tries to write to a lab-owned cache path:
export PIXI_HOME="${HOME}/.cache/hugsim/pixi"
export PIP_CACHE_DIR="${HOME}/.cache/hugsim/pip"
export UV_CACHE_DIR="${HOME}/.cache/hugsim/uv"
mkdir -p "${PIXI_HOME}" "${PIP_CACHE_DIR}" "${UV_CACHE_DIR}"pixi install tries to fetch from mirrors.zju.edu.cn and hangs or fails:
mv pixi.lock pixi.lock.zjuCUDA extension build fails:
nvidia-smi
nvcc --version
pixi run python -c "import torch; print(torch.version.cuda)"apex fails to build:
- confirm the pixi environment already imports
torch - confirm
nvccis from a CUDA toolkit compatible with the installed PyTorch build - rerun
pixi run install-apexafter the source-build pass succeeds