Record Episode

When to Use

• A scene is up (launch-scene skill) and the user wants to persist topic streams for later replay or dataset assembly.
• Teleop is running (run-teleop skill in geniesim_teleop) and the user wants ROS-side recording on top of the teleop loop's own per-episode artifacts.
• Benchmark run wants extra raw-topic capture beyond what --benchmark.record=true writes.

Do not use for:

• Replaying an already-recorded bag → just use ros2 bag play.
• Recording from a stopped sim — ros2 bag needs live publishers.

Critical Patterns

1. use_sim_time:=true is set engine-side, so every bag captures /clock and replays cleanly at simulation rate. Don't override the topic with wall-clock.
2. Always record /clock in addition to your topic list — replay without it falls back to wall-clock pacing and timing breaks for downstream learners.
3. Camera topics are heavy. A G2 scene with three cameras at 30 Hz easily clocks 200+ MB/min. Either narrow the topic list or use --max-bag-size to roll over bags.
4. One recording per run. Restart the scene between recordings — the engine's init_* blocks run only at startup, and a fresh reset is the only way to guarantee a deterministic t0.
5. ros2 bag is the canonical path. There is no dedicated "recorder" distribution in the stack — the teleop and benchmark loops have their own per-episode writers (see below), and everything else goes through ros2 bag.

What to record

Workflow

Step 1 — Confirm the scene is up

bashCopy code
ros2 topic list | grep -E "joint_states|tf|clock"
ros2 topic hz /clock                       # sim-time pacing should be live

Step 2 — Pick a topic list

For a typical G2 manipulation run:

bashCopy code
TOPICS=(
  /clock
  /tf /tf_static
  /joint_states
  /joint_command
  /odom
)
# add cameras if you want pixels:
TOPICS+=(/camera/head/rgb /camera/head/depth)

Step 3 — Start the bag

bashCopy code
# inside the container, in a second shell:
source devel/setup.bash
ros2 bag record \
  --output ./runs/$(date +%Y%m%d_%H%M%S)_${USER}_pnp \
  --max-bag-size 1073741824 \
  --storage mcap \
  "${TOPICS[@]}"

Stop with Ctrl-C. The bag dir contains metadata.yaml + chunked .mcap files.

Step 4 — Verify

bashCopy code
ros2 bag info ./runs/<dir>
ros2 bag play ./runs/<dir> --clock          # replay sim-time

Step 5 — (alternative) Let the loop record for you

For teleop:

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geniesim teleop run --device_type=pico --record-dir ./runs
# writes per-episode artifacts under ./runs/<episode>/

For benchmark:

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geniesim benchmark run <CONFIG> --infer-host=<IP>:<PORT> \
  --benchmark.record=true
# output_dir comes from the config; check the run banner

Commands (copy-paste summary for the user)

bashCopy code
# Inside the container, alongside a running scene:
source devel/setup.bash
ros2 bag record \
  --output ./runs/$(date +%Y%m%d_%H%M%S)_demo \
  --storage mcap \
  /clock /tf /tf_static /joint_states /joint_command /odom

# Replay:
ros2 bag play ./runs/<dir> --clock

Notes

• --storage mcap is preferred over the legacy sqlite3 storage — faster random access, smaller files, and the standard for ROS 2 Jazzy.
• If you plan to feed the bag to a dataset pipeline, also pin the manifest.json (under assets/scenes/<scene>/) alongside the bag — it records the exact USD + robot variant the bag was captured against.
• For dataset-scale recording, the geniesim_generator skills (generate-scene, search-assets) plus the benchmark record=true flag are the closer fit — they write episode-indexed artifacts, not raw bags.

Resources

• Teleop recording hooks: source/geniesim_teleop/skills/run-teleop/SKILL.md
• Benchmark recording flag: source/geniesim_benchmark/skills/run-benchmark/SKILL.md
• ros2 bag (Jazzy): https://docs.ros.org/en/jazzy/Tutorials/Beginner-CLI-Tools/Recording-And-Playing-Back-Data/Recording-And-Playing-Back-Data.html