Fixes navigation env config for PresetCfg compatibility

source/isaaclab_tasks/isaaclab_tasks/manager_based/navigation/config/anymal_c/navigation_env_cfg.py

@@ -17,8 +17,12 @@
 
 import isaaclab_tasks.manager_based.navigation.mdp as mdp
 from isaaclab_tasks.manager_based.locomotion.velocity.config.anymal_c.flat_env_cfg import AnymalCFlatEnvCfg
+from isaaclab_tasks.utils.hydra import resolve_presets
 
 LOW_LEVEL_ENV_CFG = AnymalCFlatEnvCfg()
+# Resolve PresetCfg wrappers (contact sensor, actuator armature, etc.) so that
+# class-level defaults referencing LOW_LEVEL_ENV_CFG fields get concrete configs.
+resolve_presets(LOW_LEVEL_ENV_CFG)
 
 
 @configclass
@@ -140,6 +144,13 @@ def __post_init__(self):
         self.decimation = LOW_LEVEL_ENV_CFG.decimation * 10
         self.episode_length_s = self.commands.pose_command.resampling_time_range[1]
 
+        # Resolve any PresetCfg wrappers in the scene so that subsequent
+        # attribute assignments target the actual configs, not wrappers that
+        # would be discarded by a later resolve_presets call.
+        resolve_presets(self.scene)
+
+        self.sim.physics_material = self.scene.terrain.physics_material
+
         if self.scene.height_scanner is not None:
             self.scene.height_scanner.update_period = (
                 self.actions.pre_trained_policy_action.low_level_decimation * self.sim.dt

source/isaaclab_tasks/test/test_navigation_env_cfg.py

@@ -0,0 +1,76 @@
+# Copyright (c) 2022-2026, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+"""Tests for the navigation environment configuration.
+
+These tests verify that PresetCfg wrappers inherited from the locomotion
+velocity environment are properly resolved in the navigation env config,
+and that sensor update periods and physics materials are correctly propagated.
+"""
+
+from isaaclab_tasks.utils.hydra import PresetCfg, resolve_presets
+
+
+class TestNavigationEnvCfg:
+    """Regression tests for NavigationEnvCfg preset resolution."""
+
+    def test_low_level_env_cfg_presets_resolved(self):
+        """LOW_LEVEL_ENV_CFG should have all PresetCfg wrappers resolved at import time."""
+        from isaaclab_tasks.manager_based.navigation.config.anymal_c.navigation_env_cfg import LOW_LEVEL_ENV_CFG
+
+        assert not isinstance(LOW_LEVEL_ENV_CFG.scene.contact_forces, PresetCfg), (
+            "LOW_LEVEL_ENV_CFG.scene.contact_forces should be a resolved ContactSensorCfg, not a PresetCfg wrapper"
+        )
+
+    def test_contact_forces_update_period(self):
+        """contact_forces.update_period must equal sim.dt after config creation."""
+        from isaaclab_tasks.manager_based.navigation.config.anymal_c.navigation_env_cfg import NavigationEnvCfg
+
+        cfg = NavigationEnvCfg()
+        resolved = resolve_presets(cfg)
+
+        assert not isinstance(resolved.scene.contact_forces, PresetCfg)
+        assert resolved.scene.contact_forces.update_period == resolved.sim.dt, (
+            f"Expected update_period={resolved.sim.dt}, got {resolved.scene.contact_forces.update_period}. "
+            "This indicates update_period was set on a PresetCfg wrapper and lost during resolution."
+        )
+
+    def test_physics_material_propagated(self):
+        """sim.physics_material should match the terrain's physics material."""
+        from isaaclab_tasks.manager_based.navigation.config.anymal_c.navigation_env_cfg import NavigationEnvCfg
+
+        cfg = NavigationEnvCfg()
+        resolved = resolve_presets(cfg)
+
+        terrain_mat = resolved.scene.terrain.physics_material
+        sim_mat = resolved.sim.physics_material
+        assert sim_mat.static_friction == terrain_mat.static_friction, (
+            f"sim.physics_material.static_friction ({sim_mat.static_friction}) != "
+            f"terrain.physics_material.static_friction ({terrain_mat.static_friction})"
+        )
+        assert sim_mat.dynamic_friction == terrain_mat.dynamic_friction
+        assert sim_mat.restitution == terrain_mat.restitution
+
+    def test_no_remaining_presets(self):
+        """No PresetCfg wrappers should remain after resolve_presets."""
+        from isaaclab_tasks.manager_based.navigation.config.anymal_c.navigation_env_cfg import NavigationEnvCfg
+        from isaaclab_tasks.utils.hydra import collect_presets
+
+        cfg = NavigationEnvCfg()
+        resolved = resolve_presets(cfg)
+        remaining = collect_presets(resolved)
+        assert len(remaining) == 0, f"Unresolved PresetCfg nodes remain: {list(remaining.keys())}"
+
+    def test_play_config(self):
+        """NavigationEnvCfg_PLAY should also resolve correctly."""
+        from isaaclab_tasks.manager_based.navigation.config.anymal_c.navigation_env_cfg import NavigationEnvCfg_PLAY
+
+        cfg = NavigationEnvCfg_PLAY()
+        resolved = resolve_presets(cfg)
+
+        assert resolved.scene.num_envs == 50
+        assert not resolved.observations.policy.enable_corruption
+        assert resolved.scene.contact_forces.update_period == resolved.sim.dt
+        assert not isinstance(resolved.scene.contact_forces, PresetCfg)