fix

Author: ooctipus

source/isaaclab/isaaclab/scene/interactive_scene.py

@@ -215,7 +215,7 @@ def __init__(self, cfg: InteractiveSceneCfg):
             if self.cfg.filter_collisions and "physx" in self.physics_backend:
                 self.filter_collisions(self._global_prim_paths)
 
-    def _build_clone_plan_from_cfg(self) -> cloner.ClonePlan:
+    def _build_clone_plan_from_cfg(self) -> cloner.ClonePlan | None:
         """Build a clone plan from scene cfg spawn variants and write planned spawn paths."""
 
         def num_variants(spawn_cfg) -> int:
@@ -251,8 +251,11 @@ def set_spawn_paths(spawn_cfg, paths: list[str | None]) -> None:
                     raise ValueError(f"Spawner at '{prim_path}' must have at least one variant.")
                 groups.append((cfg.spawn, prim_path.replace(self.env_regex_ns, self.env_fmt), count))
 
+        if not groups:
+            return None
+
         # Homogeneous scenes still spawn sources at env_0, but publish the simpler env-root plan.
-        if not groups or all(count == 1 for _, _, count in groups):
+        if all(count == 1 for _, _, count in groups):
             for spawn_cfg, destination, _ in groups:
                 set_spawn_paths(spawn_cfg, [destination.format(0)])
             return cloner.ClonePlan(
@@ -293,6 +296,12 @@ def clone_environments(self, copy_from_source: bool = False):
             If True, clones are independent copies of the source prim and won't reflect its changes (start-up time
             may increase). Defaults to False.
         """
+        plan = self._clone_plan
+        assert self.sim is not None
+        if plan is None:
+            self.sim.set_clone_plan(None)
+            return
+
         # PhysX-only: set env id bit count for replicated physics. Newton handles env separation in its own API.
         # Intentionally matches both physx and ovphysx (both are PhysX-based)
         if self.cfg.replicate_physics and "physx" in self.physics_backend:
@@ -303,7 +312,6 @@ def clone_environments(self, copy_from_source: bool = False):
         # ``SimulationContext.reset`` does the Fabric resync — re-enabling here would batch-resync everything
         # we just authored, which is slower than the unsuppressed baseline.
         with cloner.disabled_fabric_change_notifies(self.stage, restore=False):
-            plan = self._clone_plan
             replicate_args = (plan.sources, plan.destinations, self._ALL_INDICES, plan.clone_mask)
 
             if not copy_from_source and self.cloner_cfg.physics_clone_fn is not None:

source/isaaclab/test/scene/test_interactive_scene.py

@@ -214,6 +214,18 @@ def _usd_replicate(stage, *args, **kwargs):
     assert len(set_plan_calls) == 1
 
 
+def test_clone_environments_skips_replication_without_plan():
+    """Direct-path cfg scenes publish no plan and do not dispatch cloners."""
+    scene = object.__new__(InteractiveScene)
+    scene._clone_plan = None
+    set_plan_calls = []
+    scene.sim = SimpleNamespace(set_clone_plan=set_plan_calls.append)
+
+    scene.clone_environments(copy_from_source=False)
+
+    assert set_plan_calls == [None]
+
+
 def test_clone_environments_executes_asset_level_plan_without_usd_positions(monkeypatch: pytest.MonkeyPatch):
     """Asset-level plans preserve env-root transforms by skipping USD positions."""
     from isaaclab.cloner import ClonePlan
@@ -290,6 +302,7 @@ def test_build_clone_plan_from_cfg_plans_multi_and_single_spawners(monkeypatch:
 
     plan = scene._build_clone_plan_from_cfg()
 
+    assert plan is not None
     assert plan.sources == [
         "/World/envs/env_0/Object",
         "/World/envs/env_1/Object",
@@ -325,12 +338,33 @@ def test_build_clone_plan_from_cfg_defaults_to_env0_plan(monkeypatch: pytest.Mon
 
     plan = scene._build_clone_plan_from_cfg()
 
+    assert plan is not None
     assert plan.sources == ["/World/envs/env_0"]
     assert plan.destinations == [scene.env_fmt]
     assert plan.clone_mask.shape == (1, scene.num_envs)
     assert scene.cfg.robot.spawn.spawn_path == "/World/envs/env_0/Robot"
 
 
+def test_build_clone_plan_from_cfg_returns_none_without_env_scoped_groups(monkeypatch: pytest.MonkeyPatch):
+    """Direct-path cfg scenes should not force env-root replication."""
+    from isaaclab.cloner import sequential
+
+    scene = object.__new__(InteractiveScene)
+    scene.cfg = SimpleNamespace(
+        num_envs=1,
+        robot=SimpleNamespace(
+            prim_path="/World/Robot",
+            spawn=sim_utils.CuboidCfg(size=(0.1, 0.1, 0.1)),
+        ),
+    )
+    scene.env_fmt = "/World/envs/env_{}"
+    scene.cloner_cfg = SimpleNamespace(clone_strategy=sequential)
+    monkeypatch.setattr(InteractiveScene, "device", property(lambda self: "cpu"))
+
+    assert scene._build_clone_plan_from_cfg() is None
+    assert scene.cfg.robot.spawn.spawn_path is None
+
+
 def test_build_clone_plan_from_cfg_sets_collection_member_paths(monkeypatch: pytest.MonkeyPatch):
     """Rigid object collection members are planned independently."""
     from isaaclab.cloner import sequential
@@ -356,6 +390,7 @@ def test_build_clone_plan_from_cfg_sets_collection_member_paths(monkeypatch: pyt
 
     plan = scene._build_clone_plan_from_cfg()
 
+    assert plan is not None
     planned_cube = scene.cfg.objects.rigid_objects["cube"]
     planned_shape = scene.cfg.objects.rigid_objects["shape"]
     assert planned_cube.spawn.spawn_path == "/World/envs/env_0/Cube"
@@ -388,6 +423,7 @@ def test_build_clone_plan_from_cfg_marks_unused_variants(monkeypatch: pytest.Mon
 
     plan = scene._build_clone_plan_from_cfg()
 
+    assert plan is not None
     assert scene.cfg.object.spawn.spawn_paths == ["/World/envs/env_0/Object", "/World/envs/env_1/Object", None]
     assert plan.clone_mask[2].sum() == 0