multiple simulation manager

docs/source/overview/sim/sim_manager.md

@@ -26,6 +26,10 @@ sim_config = SimulationManagerCfg(
 )
 ```
 
+### multiple instance
+- current instance number of `SimulationManager`: `SimulationManager.get_n_instances()`
+- get specific instance: `SimulationManager.get_instance(instance_id)`, `instance_id` < `SimulationManager.get_n_instances()`
+
 ### Configuration Parameters
 
 | Parameter | Type | Default | Description |

embodichain/lab/sim/sim_manager.py

@@ -158,41 +158,52 @@ class SimulationManager:
             - physics simulation management, eg. time step, manual update, etc.
             - interactive control via gizmo and window callbacks events.
 
-    This class implements the singleton pattern to ensure only one instance exists at a time.
-
     Args:
         sim_config (SimulationManagerCfg, optional): simulation configuration. Defaults to SimulationManagerCfg().
     """
 
-    _instance = None
-    _is_initialized = False
+    _instances = {}
 
     SUPPORTED_SENSOR_TYPES = {
         "Camera": Camera,
         "StereoCamera": StereoCamera,
         "ContactSensor": ContactSensor,
     }
 
-    def __new__(cls, sim_config: SimulationManagerCfg = SimulationManagerCfg()):
-        """Create or return the singleton instance."""
-        if cls._instance is None:
-            cls._instance = super(SimulationManager, cls).__new__(cls)
-        return cls._instance
+    def __new__(
+        cls,
+        sim_config: SimulationManagerCfg = SimulationManagerCfg()
+    ):
+        """Create or return the instance based on instance_id."""
+        n_instance = len(list(cls._instances.keys()))
+        instance = super(SimulationManager, cls).__new__(cls)
+        # Store sim_config in the instance for use in __init__ or elsewhere
+        instance.sim_config = sim_config
+        cls._instances[str(n_instance + 1)] = instance
+        return instance
 
     def __init__(
-        self, sim_config: SimulationManagerCfg = SimulationManagerCfg()
+        self,
+        sim_config: SimulationManagerCfg = SimulationManagerCfg()
     ) -> None:
+        instance_id = SimulationManager.get_n_instances() + 1
         # Skip initialization if already initialized
-        if self._is_initialized:
+        if hasattr(self, "_is_initialized") and self._is_initialized:
             logger.log_warning(
-                "SimulationManager is already initialized. Skipping re-initialization. "
-                "Use SimulationManager.get_instance() to get the existing instance or "
-                "SimulationManager.reset() to create a new instance."
+                f"SimulationManager (id={instance_id}) is already initialized. Skipping re-initialization. "
+                "Use SimulationManager.get_instance(instance_id) to get the existing instance or "
+                "SimulationManager.reset(instance_id) to create a new instance."
             )
             return
 
+        if sim_config.enable_rt and instance_id > 0:
+            logger.log_error(
+                f"Ray Tracing rendering backend is only supported for single instance (instance_id=0). "
+            )
+
         # Mark as initialized
-        SimulationManager._is_initialized = True
+        self._is_initialized = True
+        self.instance_id = instance_id
         # Cache paths
         self._sim_cache_dir = SIM_CACHE_DIR
         self._material_cache_dir = MATERIAL_CACHE_DIR
@@ -278,41 +289,52 @@ def __init__(
         self._build_multiple_arenas(sim_config.num_envs)
 
     @classmethod
-    def get_instance(cls) -> SimulationManager:
-        """Get the singleton instance of SimulationManager.
+    def get_instance(cls, instance_id: int = 0) -> SimulationManager:
+        """Get the instance of SimulationManager by id.
+
+        Args:
+            instance_id (int): The instance id. Defaults to 0.
 
         Returns:
-            SimulationManager: The singleton instance.
+            SimulationManager: The instance.
 
         Raises:
             RuntimeError: If the instance has not been created yet.
         """
-        if cls._instance is None:
+        if instance_id not in cls._instances:
             logger.log_error(
-                "SimulationManager has not been instantiated yet. "
-                "Create an instance first using SimulationManager(sim_config)."
+                f"SimulationManager (id={instance_id}) has not been instantiated yet. "
+                f"Create an instance first using SimulationManager(sim_config, instance_id={instance_id})."
             )
-        return cls._instance
+        return cls._instances[instance_id]
+
+    @classmethod
+    def get_n_instances(cls) -> int:
+        """Get the number of instantiated SimulationManager instances.
+
+        Returns:
+            int: The number of instances.
+        """
+        return len(cls._instances)
 
     @classmethod
-    def reset(cls) -> None:
-        """Reset the singleton instance.
+    def reset(cls, instance_id: int = 0) -> None:
+        """Reset the instance.
 
         This allows creating a new instance with different configuration.
         """
-        if cls._instance is not None:
-            logger.log_info("Resetting SimulationManager singleton instance.")
-        cls._instance = None
-        cls._is_initialized = False
+        if instance_id in cls._instances:
+            logger.log_info(f"Resetting SimulationManager instance {instance_id}.")
+            del cls._instances[instance_id]
 
     @classmethod
-    def is_instantiated(cls) -> bool:
-        """Check if the singleton instance has been created.
+    def is_instantiated(cls, instance_id: int = 0) -> bool:
+        """Check if the instance has been created.
 
         Returns:
             bool: True if the instance exists, False otherwise.
         """
-        return cls._instance is not None
+        return instance_id in cls._instances
 
     @property
     def num_envs(self) -> int:
@@ -1560,4 +1582,4 @@ def destroy(self) -> None:
         self._env.clean()
         self._world.quit()
 
-        self.reset()
+        SimulationManager.reset(self.instance_id)