Initial snapshot: hand motion pipeline (Dyn-HaMR + dex-retargeting + SPIDER)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

scripts/play_l20_motion.py

@@ -0,0 +1,51 @@
+"""Play a hand-only L20 motion file with a free wrist in MuJoCo."""
+import argparse
+import time
+import mujoco
+import mujoco.viewer
+import numpy as np
+
+p = argparse.ArgumentParser()
+p.add_argument('--directory', required=True)
+a = p.parse_args()
+from pathlib import Path
+directory = Path(a.directory)
+with np.load(directory / 'motion.npz') as data:
+    motion = {name:data[name] for name in data.files}
+model = mujoco.MjModel.from_xml_path(str(directory / 'l20_moving.xml'))
+data = mujoco.MjData(model)
+addr = [model.jnt_qposadr[model.joint(str(n)).id] for n in motion['joint_names']]
+wrist = model.jnt_qposadr[model.joint('wrist_free').id]
+fps = float(motion['fps'])
+count = len(motion['qpos'])
+state = dict(frame=0., paused=False)
+
+def key(k):
+    if k == 32:
+        state['paused'] = not state['paused']
+    elif k in [82,114]:
+        state['frame'] = 0.
+    elif k in [262,263]:
+        state['frame'] = (int(state['frame']) + (1 if k == 262 else -1)) % count
+        state['paused'] = True
+
+with mujoco.viewer.launch_passive(model, data, key_callback=key) as viewer:
+    viewer.cam.lookat[:] = motion['wrist_pos'].mean(0)
+    viewer.cam.distance = .9
+    viewer.cam.azimuth, viewer.cam.elevation = 135, 10
+    viewer.opt.sitegroup[:] = 0
+    last = time.perf_counter()
+    while viewer.is_running():
+        now = time.perf_counter()
+        if not state['paused']:
+            state['frame'] = (state['frame'] + (now-last)*fps) % count
+        last = now
+        t = int(state['frame'])
+        with viewer.lock():
+            data.qpos[addr] = motion['qpos'][t]
+            data.qpos[wrist:wrist+3] = motion['wrist_pos'][t]
+            data.qpos[wrist+3:wrist+7] = motion['wrist_quat_wxyz'][t]
+            data.time = t/fps
+            mujoco.mj_forward(model,data)
+        viewer.sync()
+        time.sleep(.005)