I4h workflow dataset replay
Agent Skills for NVIDIA products — install into Claude Code, Codex, and other coding agents to run Physical AI, robotics, simulation, CUDA, and RAG workflows end to end.
npx -y skills add NVIDIA/skills --skill i4h-workflow-dataset-replayAssembled from the repository path, not quoted from the project. Check it against their README if it does not work.
What its author says it does
Copied from the file, not written here
Replay a recorded HDF5 episode inside Isaac Sim for visual verification. Use when the user asks to replay, play back, or step through an HDF5 recording.
The file declares its own license as Apache-2.0. That is the author’s claim about this one file, and it is not the same thing as the license GitHub reports for the repository, which is listed with the other numbers below.
SKILL.md
4.9 KB, ~1.3k tokens by cl100k_base, as published. Nobody here has run it
i4h Workflow — Replay Dataset
Purpose
Replay a recorded HDF5 episode inside Isaac Sim for visual verification. Use when the user asks to replay, play back, or step through an HDF5 recording.
Base Code
These steps drive the i4h-workflows base code (the workflows/agentic/ tree). To reuse an existing checkout, set I4H_WORKFLOWS to its path (no clone happens). Otherwise this resolves the current repo, or clones to ~/i4h-workflows — pick that default without prompting. Run every command below from the resolved root:
# Resolve the i4h-workflows base code (provides workflows/agentic/).
ROOT="${I4H_WORKFLOWS:-$(git rev-parse --show-toplevel 2>/dev/null)}"
if [ ! -d "$ROOT/workflows/agentic" ]; then
ROOT="${I4H_WORKFLOWS:-$HOME/i4h-workflows}"
[ -d "$ROOT/workflows/agentic" ] || git clone https://github.com/isaac-for-healthcare/i4h-workflows "$ROOT"
fi
export I4H_WORKFLOWS="$ROOT"; cd "$ROOT"
Basics
- Env config (source of truth):
workflows/agentic/config/environments/<env>.yaml— the<env>scene, robot, and cameras Arena replays against. - Replay runs
arena/run.sh --replayagainst the env that produced the HDF5. - Use it to verify visual correctness before conversion or training.
- Interpret ordinal wording as zero-based episode indices: "first episode" ->
0, "second episode" ->1, etc.
Run
Run the steps below in order. Each step is a separate bash call; variables persist in the local agent's tmux session.
Step 1 — setup and resolve HDF5
REPO_ROOT="${I4H_WORKFLOWS:-$(git rev-parse --show-toplevel 2>/dev/null)}"; [ -d "$REPO_ROOT/workflows/agentic" ] || REPO_ROOT="$HOME/i4h-workflows"
ENV_ID=scissor_pick_and_place
RUNS_ROOT="${REPO_ROOT}/workflows/agentic/runs"
EPISODE_INDEX="${EPISODE_INDEX:-0}" # For "Replay second episode", set EPISODE_INDEX=1.
# Point HDF5_PATH at a real recording (absolute path). Recordings come from teleop, mimic, or
# validate (which writes data/verify.hdf5 under each runs/eval_* dir). List candidates newest-first:
# find "${RUNS_ROOT}" -name '*.hdf5' -printf '%TY-%Tm-%Td %TH:%TM %p\n' | sort -r | head
HDF5_PATH="${HDF5_PATH:-}"
if [ ! -f "${HDF5_PATH}" ]; then
echo "replay: set HDF5_PATH to an existing .hdf5 (got '${HDF5_PATH:-<unset>}'). Candidates:" >&2
find "${RUNS_ROOT}" -name '*.hdf5' -printf '%TY-%Tm-%Td %TH:%TM %p\n' 2>/dev/null | sort -r | head
exit 1
fi
RUN_DIR="${RUNS_ROOT}/replay_${ENV_ID}_$(date +%Y%m%d_%H%M%S)"
mkdir -p "${RUN_DIR}/logs"
ln -sfn "${RUN_DIR}" "${RUNS_ROOT}/.latest"
Step 2 — replay
"${REPO_ROOT}/workflows/agentic/arena/run.sh" \
--env "${ENV_ID}" \
--replay "${HDF5_PATH}" \
--episode-index "${EPISODE_INDEX}" \
2>&1 | tee "${RUN_DIR}/logs/replay.log"
Notes
HDF5_PATHmust be an absolute path to an existing recording —--replayresolves a relative path againstruns/<env>/, not your cwd, so a bare/relative path silently fails to load. The block lists real candidates if it's unset or wrong.- Recordings come from [[i4h-workflow-dataset-teleop]], [[i4h-workflow-dataset-mimic]], or [[i4h-workflow-validate]] (validate writes
data/verify.hdf5under eachruns/eval_*dir). There is no defaultdemo.hdf5. --episode-indexselects the episode within the HDF5 (zero-based).- For "Replay second episode", use
--episode-index 1. - Use the same env id as the env that produced the recording.
Prerequisites
- Workflow set up via [[i4h-workflow-setup]] (the
.venvmust exist). - An existing HDF5 recording to replay.
- The env id that produced the recording.
Limitations
- Visual verification only; replay does not modify or expand the recording.
- Replays one episode per invocation, selected by
--episode-index. - Runs inside Isaac Sim; the env id must match the one that produced the HDF5.
Troubleshooting
- Error:
.venvnot found / replay fails to launch - Cause: workflow not set up. Fix: run [[i4h-workflow-setup]] first. - Error:
replay: set HDF5_PATH to an existing .hdf5(or recording fails to load) - Cause:HDF5_PATHunset or not a real file. Fix: pick an absolute path from the printed candidates (e.g. averify.hdf5underruns/eval_*/data/). - Error: episode index out of range - Cause:
--episode-indexexceeds the episodes in the HDF5. Fix: use a valid zero-based index. - Error: mismatched/garbled playback - Cause:
--envdiffers from the env that produced the recording. Fix: use the same env id.
Final Response
Report env, HDF5 path, episode index, launch outcome, visible mismatches.