(fix) hardcode smpl_skeleton, remove .npz

src/lerobot/teleoperators/pico_headset/smpl_fk.py

@@ -19,7 +19,8 @@
 This mirrors the ``rt/smpl`` producer path in ``gear_sonic`` (``compute_from_body_poses``
 -> ``process_smpl_joints`` -> ``compute_human_joints``) without depending on torch,
 the SMPL mesh model, or ``gear_sonic``. It only needs a small fixed skeleton table
-(rest-pose joints + kinematic tree), vendored in ``assets/smpl_skeleton.npz``.
+(SMPL-X rest-pose joints + kinematic tree), hardcoded below as ``_SKELETON_J`` /
+``_SKELETON_PARENTS`` so no external asset download is required.
 
 Given the 24 body-joint poses reported by the XRoboToolkit headset SDK
 (``xrt.get_body_joints_pose()`` -> (24, 7) of ``[x, y, z, qx, qy, qz, qw]``), it
@@ -44,7 +45,76 @@ BODY24_PARENTS = np.array(
 # FK output joints: first 22 SMPL body joints + two thumb tips (SMPL-X indices 39, 54).
 OUTPUT_JOINT_INDEX = np.concatenate([np.arange(22), np.array([39, 54])])
 
-_SKELETON_PATH = Path(__file__).parent / "assets" / "smpl_skeleton.npz"
+# SMPL-X rest-pose skeleton (55 joints), vendored inline to avoid an external
+# asset. ``_SKELETON_PARENTS[i]`` is joint ``i``'s parent (-1 = root); ``_SKELETON_J``
+# holds the (55, 3) rest-pose joint positions.
+_SKELETON_PARENTS = np.array(
+    [-1, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 9, 9, 12, 13, 14, 16, 17, 18, 19, 15, 15, 15,
+     20, 25, 26, 20, 28, 29, 20, 31, 32, 20, 34, 35, 20, 37, 38, 21, 40, 41, 21, 43, 44,
+     21, 46, 47, 21, 49, 50, 21, 52, 53],
+    dtype=np.int64,
+)
+
+_SKELETON_J = np.array(
+    [
+        [0.0031232605688273907, -0.3514074683189392, 0.012036550790071487],
+        [0.06131265312433243, -0.4441709518432617, -0.013964635320007801],
+        [-0.06014421582221985, -0.4553154706954956, -0.009213820099830627],
+        [0.00036056205863133073, -0.2415168583393097, -0.015581080690026283],
+        [0.11600811034440994, -0.8229243755340576, -0.02336069941520691],
+        [-0.10435417294502258, -0.8176955580711365, -0.026037702336907387],
+        [0.009808260947465897, -0.10966360569000244, -0.02152106538414955],
+        [0.07255466282367706, -1.2259838581085205, -0.05523664504289627],
+        [-0.08893736451864243, -1.2284233570098877, -0.046229973435401917],
+        [-0.0015221529174596071, -0.057428449392318726, 0.006925832014530897],
+        [0.11981196701526642, -1.283981204032898, 0.06297968327999115],
+        [-0.12774977087974548, -1.2867517471313477, 0.07281902432441711],
+        [-0.01368661131709814, 0.10773860663175583, -0.024689510464668274],
+        [0.04484200477600098, 0.027515273541212082, -0.0002946509048342705],
+        [-0.04921707883477211, 0.026910223066806793, -0.006474069785326719],
+        [0.011096873320639133, 0.2681904137134552, -0.003952245227992535],
+        [0.16408103704452515, 0.08524329960346222, -0.015755590051412582],
+        [-0.15179482102394104, 0.08043467253446579, -0.019142597913742065],
+        [0.4182038903236389, 0.01309278141707182, -0.058214444667100906],
+        [-0.4229443669319153, 0.04394219070672989, -0.04560968279838562],
+        [0.6701906323432922, 0.03631401062011719, -0.06068652495741844],
+        [-0.6722118258476257, 0.03940964490175247, -0.06093486770987511],
+        [-0.004667762666940689, 0.2676706910133362, -0.009591402485966682],
+        [0.03159928321838379, 0.31083211302757263, 0.062195174396038055],
+        [-0.031599875539541245, 0.3108319342136383, 0.0621943436563015],
+        [0.7720924615859985, 0.02762586995959282, -0.04133538901805878],
+        [0.8040408492088318, 0.02984413132071495, -0.03832494467496872],
+        [0.8265857696533203, 0.027494050562381744, -0.03827037289738655],
+        [0.7795881628990173, 0.029986342415213585, -0.06466733664274216],
+        [0.8101993799209595, 0.030793743208050728, -0.0686899945139885],
+        [0.8337147831916809, 0.028784994035959244, -0.07280422002077103],
+        [0.7542374730110168, 0.02177468128502369, -0.10443613678216934],
+        [0.7697082161903381, 0.020643100142478943, -0.11643557250499725],
+        [0.7852417230606079, 0.018978532403707504, -0.12765252590179443],
+        [0.767634928226471, 0.02704637683928013, -0.08803117275238037],
+        [0.7956817150115967, 0.028531836345791817, -0.09329714626073837],
+        [0.8185034990310669, 0.02707355096936226, -0.1003914326429367],
+        [0.7108263969421387, 0.01833728514611721, -0.03507564589381218],
+        [0.7278420925140381, 0.01931309886276722, -0.010097505524754524],
+        [0.7483652234077454, 0.01415354385972023, 0.005425570998340845],
+        [-0.7720924019813538, 0.027626780793070793, -0.041334930807352066],
+        [-0.8040405511856079, 0.029844673350453377, -0.03832409530878067],
+        [-0.8265854716300964, 0.027495287358760834, -0.03826868534088135],
+        [-0.7795882225036621, 0.029987698420882225, -0.0646686926484108],
+        [-0.8101993799209595, 0.030795171856880188, -0.06869153678417206],
+        [-0.8337149024009705, 0.02878585271537304, -0.07280556112527847],
+        [-0.7542385458946228, 0.021775206550955772, -0.10443780571222305],
+        [-0.7697089910507202, 0.02064313367009163, -0.11643654853105545],
+        [-0.7852423787117004, 0.01897839829325676, -0.1276528388261795],
+        [-0.7676352858543396, 0.02704770304262638, -0.08803359419107437],
+        [-0.7956817150115967, 0.028532907366752625, -0.093299500644207],
+        [-0.818503737449646, 0.027074117213487625, -0.10039224475622177],
+        [-0.7108249664306641, 0.018335221335291862, -0.035073522478342056],
+        [-0.7278403043746948, 0.019311318174004555, -0.01009594276547432],
+        [-0.7483659386634827, 0.014154116623103619, 0.005425604991614819],
+    ],
+    dtype=np.float32,
+)
 
 
 # ── quaternion helpers (scalar-first w, x, y, z) ─────────────────────────────
@@ -153,10 +223,14 @@ def root_quats_from_aa(root_aa: np.ndarray) -> np.ndarray:
 class SmplForwardKinematics:
     """Rest-skeleton SMPL forward kinematics (no mesh, no torch)."""
 
-    def __init__(self, skeleton_path: str | Path = _SKELETON_PATH):
-        data = np.load(skeleton_path)
-        self.J = data["J"].astype(np.float64)  # (55, 3) rest joint positions
-        self.parents = data["parents"].astype(np.int64)  # (55,) kinematic tree
+    def __init__(self, skeleton_path: str | Path | None = None):
+        if skeleton_path is not None:
+            data = np.load(skeleton_path)
+            self.J = data["J"].astype(np.float64)  # (55, 3) rest joint positions
+            self.parents = data["parents"].astype(np.int64)  # (55,) kinematic tree
+        else:
+            self.J = _SKELETON_J.astype(np.float64)
+            self.parents = _SKELETON_PARENTS.copy()
         self.n_joints = self.J.shape[0]
 
     def _fk(self, full_pose_aa: np.ndarray) -> np.ndarray: