regenerate-model

name	regenerate-model
description	Regenerate the committed MJCF snapshot models/stackchan/stackchan.xml from params.py after physical parameters change, then show the diff. Use after editing params.py or model.py.

Regenerate the MJCF snapshot

models/stackchan/stackchan.xml is a committed snapshot of the default profile, generated from params.py via model.write_model(...). It is NOT hand-edited (a PreToolUse hook blocks manual edits). Whenever params.py or model.py changes in a way that affects the default profile, regenerate the snapshot so it stays in sync with the single source of truth.

Steps

1. Regenerate the default snapshot (default profile = report, servo = SCS0009, written with meshdir="meshes"). The package is not installed into the venv, so add src to the path (mirrors how scripts/ and tests/conftest.py import it):

   uv run python -c "import sys; sys.path.insert(0, 'src'); from stackchan_sim import model; print(model.write_model('models/stackchan/stackchan.xml'))"
   

   To regenerate a non-default profile/servo, pass them explicitly:

   uv run python -c "import sys; sys.path.insert(0, 'src'); from stackchan_sim import model; model.write_model('models/stackchan/stackchan.xml', profile='report', servo='SCS0009')"
   

2. Show what changed so the diff can be reviewed before committing:

   git diff -- models/stackchan/stackchan.xml
   

3. Sanity-check that the model still loads and the tests pass:

   uv run pytest -q
   

Notes

• The one-liners add src to sys.path because the package is not installed into the venv (run uv sync first if MuJoCo/numpy imports fail).
• If the diff is empty, the snapshot was already up to date — nothing to commit.
• Report the diff summary and test result; do not commit unless asked.