Make the Push EE yaw offset a per-robot property

predicators/ground_truth_models/fan/processes.py

@@ -19,7 +19,7 @@ def _push_sampler(state: State, goal: Set[GroundAtom],
     """Return fixed push params for fan switch push.
 
     Approach 0.075 sits in a measured window: with the side-oriented
-    gripper (default skill_push_ee_yaw_offset 0) the hand extends along
+    gripper (the fetch's push_ee_yaw_offset, 0) the hand extends along
     the approach axis, so below ~0.073 the descend waypoint collides
     with an end-of-row switch (BiRRT goal-in-collision), while at 0.08
     the far-side (Off-push) waypoint already stalls at the fetch arm's

predicators/ground_truth_models/skill_factories/push.py

@@ -59,7 +59,7 @@ def _get_domino_pose(state, objects, params, config):
 from predicators.structs import Array, Object, ParameterizedOption, State, Type
 
 # Canonical continuous parameters for Push. The approach upper bound
-# leaves room for the side-oriented gripper (skill_push_ee_yaw_offset 0),
+# leaves room for a side-oriented gripper (yaw offset 0),
 # whose body extends along the approach axis: a descend waypoint closer
 # than ~0.07 m can itself collide with the pushed object. That caveat is
 # stated in the description because the tool-facing params text is the
@@ -75,6 +75,17 @@ def _get_domino_pose(state, objects, params, config):
 ]
 
 
+def resolve_ee_yaw_offset(config: SkillConfig) -> float:
+    """The EE yaw offset Push should use, in radians.
+
+    Which face of the gripper leads into the object is a property of the
+    hand, so it comes from the robot unless the config forces one.
+    """
+    if CFG.skill_push_ee_yaw_offset is None:
+        return config.robot.push_ee_yaw_offset
+    return float(CFG.skill_push_ee_yaw_offset)
+
+
 def create_push_skill(
     name: str,
     types: Sequence[Type],
@@ -133,7 +144,7 @@ def _waypoints(
         push_xy = obj_xy
         home_xy = np.array(cfg.robot_home_pos[:2])
         home_z = cfg.robot_home_pos[2]
-        ee_yaw = oyaw + CFG.skill_push_ee_yaw_offset
+        ee_yaw = oyaw + resolve_ee_yaw_offset(cfg)
         return [
             (*behind_xy, cfg.transport_z, ee_yaw, "closed"),
             (*behind_xy, oz + s_offset_z, ee_yaw, "closed"),

predicators/pybullet_helpers/robots/panda.py

@@ -84,6 +84,12 @@ def closed_fingers(self) -> float:
             return float(CFG.pybullet_closed_fingers)
         return 0.03
 
+    @property
+    def push_ee_yaw_offset(self) -> float:
+        # The Franka Hand leads with its knuckles spanning the
+        # object's face.
+        return np.pi / 2
+
     @classmethod
     def ikfast_info(cls) -> Optional[IKFastInfo]:
         return IKFastInfo(

predicators/pybullet_helpers/robots/single_arm.py

@@ -237,6 +237,18 @@ def closed_fingers(self) -> float:
         """The value at which the finger joints should be closed."""
         raise NotImplementedError("Override me!")
 
+    @property
+    def push_ee_yaw_offset(self) -> float:
+        """End-effector yaw during Push, relative to the pushed object's yaw.
+
+        Defaults to 0.0, which is what the Fetch hand was verified with
+        on domino chains and fan/boil switches (2026-07-14). A gripper
+        whose geometry differs overrides this.
+        ``CFG.skill_push_ee_yaw_offset`` overrides it for everyone when
+        set, for experiments.
+        """
+        return 0.0
+
     @classmethod
     def home_arm_joint_positions(cls) -> Optional[List[float]]:
         """The robot's canonical home configuration (arm joints only, no

predicators/settings.py

@@ -463,16 +463,9 @@ class GlobalSettings:
 
     # skill phase parameters
     skill_phase_use_motion_planning = False
-    # EE yaw relative to the pushed object's yaw during Push. The default
-    # (0.0, "side push") leads with the gripper's narrow side, shrinking
-    # the swept width so the stroke and retreat are less likely to clip
-    # neighbors (verified equivalent to the legacy front push on domino
-    # chains and fan/boil switches, 2026-07-14). pi/2 restores the legacy
-    # front push (knuckles spanning the object's face). Side push makes
-    # the hand longer ALONG the approach axis, so pushes need a real
-    # approach distance (a zero-length stroke cannot drag a switch, and
-    # a too-small offset can put the descend waypoint in collision).
-    skill_push_ee_yaw_offset = 0.0
+    # EE yaw relative to the pushed object's yaw during Push. None (the
+    # default) takes it from the robot.
+    skill_push_ee_yaw_offset = None
 
     # coffee env parameters
     coffee_num_cups_train = [1, 2]

tests/pybullet_helpers/robots/test_panda.py

@@ -182,3 +182,8 @@ def test_panda_home_keeps_canonical_arm_under_rolled_orientation(
     assert np.allclose(panda.get_state()[:3],
                        rolled_home_pose.position,
                        atol=1e-3)
+
+
+def test_panda_pushes_with_its_front_face(panda):
+    """The Franka Hand pushes front-on, unlike the base class's default."""
+    assert panda.push_ee_yaw_offset == pytest.approx(np.pi / 2)

tests/test_skill_factories.py

@@ -20,7 +20,7 @@
 from predicators.ground_truth_models.skill_factories.place import \
     create_place_skill
 from predicators.ground_truth_models.skill_factories.push import \
-    create_push_skill
+    create_push_skill, resolve_ee_yaw_offset
 from predicators.ground_truth_models.skill_factories.wait import \
     create_wait_option
 from predicators.pybullet_helpers.geometry import Pose
@@ -1153,6 +1153,26 @@ def test_push_policy_close_fingers_returns_valid_action(self, robot_scene):
         assert isinstance(action, Action)
         assert robot.action_space.contains(action.arr)
 
+    def test_ee_yaw_offset_comes_from_the_robot(self, robot_scene):
+        """With no config override, the hand decides the push orientation."""
+        _, robot = robot_scene
+        utils.reset_config({"seed": 123, "skill_push_ee_yaw_offset": None})
+        config = self._make_push_config(robot)
+        # The fetch pushes with the 0.0 default.
+        assert resolve_ee_yaw_offset(config) == robot.push_ee_yaw_offset == 0.0
+
+    def test_ee_yaw_offset_config_override_wins(self, robot_scene):
+        """Setting the flag forces one offset regardless of the robot."""
+        _, robot = robot_scene
+        utils.reset_config({
+            "seed": 123,
+            "skill_push_ee_yaw_offset": np.pi / 2
+        })
+        config = self._make_push_config(robot)
+        assert resolve_ee_yaw_offset(config) == pytest.approx(np.pi / 2)
+        assert robot.push_ee_yaw_offset == 0.0
+        utils.reset_config({"seed": 123})
+
 
 def test_fmt_option_params():
     """Params render compactly for failure messages, including empty."""