Simplifies the return type for `parse_env_cfg` method (#965)

# Description

Previously, the returned config object for `parse_env_cfg` mentioned the
dictionary. However, this is hardly used or supported in our workflows
code. This MR simplifies the return type to only be an instance of
manager-based or direct environment configuration classes. Doing so,
also cleans the code a bit by removing the need of explicit
type-hinting.

## Type of change

- Breaking change (fix or feature that would cause existing
functionality to not work as expected)

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

---------
Signed-off-by: Mayank Mittal <12863862+Mayankm96@users.noreply.github.com>

source/extensions/omni.isaac.lab_tasks/omni/isaac/lab_tasks/utils/parse_cfg.py

@@ -13,11 +13,10 @@ import os
 import re
 import yaml
 
-from omni.isaac.lab.envs import ManagerBasedRLEnvCfg
-from omni.isaac.lab.utils import update_class_from_dict, update_dict
+from omni.isaac.lab.envs import DirectRLEnvCfg, ManagerBasedRLEnvCfg
 
 
-def load_cfg_from_registry(task_name: str, entry_point_key: str) -> dict | ManagerBasedRLEnvCfg:
+def load_cfg_from_registry(task_name: str, entry_point_key: str) -> dict | object:
     """Load default configuration given its entry point from the gym registry.
 
     This function loads the configuration object from the gym registry for the given task name.
@@ -46,7 +45,8 @@ def load_cfg_from_registry(task_name: str, entry_point_key: str) -> dict | Manag
         entry_point_key: The entry point key to resolve the configuration file.
 
     Returns:
-        The parsed configuration object. This is either a dictionary or a class object.
+        The parsed configuration object. If the entry point is a YAML file, it is parsed into a dictionary.
+        If the entry point is a Python class, it is instantiated and returned.
 
     Raises:
         ValueError: If the entry point key is not available in the gym registry for the task.
@@ -98,7 +98,7 @@ def load_cfg_from_registry(task_name: str, entry_point_key: str) -> dict | Manag
 
 def parse_env_cfg(
     task_name: str, device: str = "cuda:0", num_envs: int | None = None, use_fabric: bool | None = None
-) -> dict | ManagerBasedRLEnvCfg:
+) -> ManagerBasedRLEnvCfg | DirectRLEnvCfg:
     """Parse configuration for an environment and override based on inputs.
 
     Args:
@@ -110,35 +110,28 @@ def parse_env_cfg(
             Defaults to None, in which case it is left unchanged.
 
     Returns:
-        The parsed configuration object. This is either a dictionary or a class object.
+        The parsed configuration object.
 
     Raises:
-        ValueError: If the task name is not provided, i.e. None.
+        RuntimeError: If the configuration for the task is not a class. We assume users always use a class for the
+            environment configuration.
     """
-    # check if a task name is provided
-    if task_name is None:
-        raise ValueError("Please provide a valid task name. Hint: Use --task <task_name>.")
-    # create a dictionary to update from
-    args_cfg = {"sim": {"physx": dict()}, "scene": dict()}
+    # load the default configuration
+    cfg = load_cfg_from_registry(task_name, "env_cfg_entry_point")
 
-    # simulation device
-    args_cfg["sim"]["device"] = device
+    # check that it is not a dict
+    # we assume users always use a class for the configuration
+    if isinstance(cfg, dict):
+        raise RuntimeError(f"Configuration for the task: '{task_name}' is not a class. Please provide a class.")
 
+    # simulation device
+    cfg.sim.device = device
     # disable fabric to read/write through USD
     if use_fabric is not None:
-        args_cfg["sim"]["use_fabric"] = use_fabric
-
+        cfg.sim.use_fabric = use_fabric
     # number of environments
     if num_envs is not None:
-        args_cfg["scene"]["num_envs"] = num_envs
-
-    # load the default configuration
-    cfg = load_cfg_from_registry(task_name, "env_cfg_entry_point")
-    # update the main configuration
-    if isinstance(cfg, dict):
-        cfg = update_dict(cfg, args_cfg)
-    else:
-        update_class_from_dict(cfg, args_cfg)
+        cfg.scene.num_envs = num_envs
 
     return cfg
 
@@ -165,12 +158,13 @@ def get_checkpoint_path(
         sort_alpha: Whether to sort the runs by alphabetical order. Defaults to True.
             If False, the folders in :attr:`run_dir` are sorted by the last modified time.
 
+    Returns:
+        The path to the model checkpoint.
+
     Raises:
         ValueError: When no runs are found in the input directory.
         ValueError: When no checkpoints are found in the input directory.
 
-    Returns:
-        The path to the model checkpoint.
     """
     # check if runs present in directory
     try:

source/extensions/omni.isaac.lab_tasks/test/test_environments.py

@@ -21,8 +21,6 @@ import unittest
 import carb
 import omni.usd
 
-from omni.isaac.lab.envs import ManagerBasedRLEnv, ManagerBasedRLEnvCfg
-
 import omni.isaac.lab_tasks  # noqa: F401
 from omni.isaac.lab_tasks.utils.parse_cfg import parse_env_cfg
 
@@ -88,9 +86,9 @@ class TestEnvironments(unittest.TestCase):
         # create a new stage
         omni.usd.get_context().new_stage()
         # parse configuration
-        env_cfg: ManagerBasedRLEnvCfg = parse_env_cfg(task_name, device=device, num_envs=num_envs)
+        env_cfg = parse_env_cfg(task_name, device=device, num_envs=num_envs)
         # create environment
-        env: ManagerBasedRLEnv = gym.make(task_name, cfg=env_cfg)
+        env = gym.make(task_name, cfg=env_cfg)
 
         # disable control on stop
         env.unwrapped.sim._app_control_on_stop_handle = None  # type: ignore

source/extensions/omni.isaac.lab_tasks/test/test_record_video.py

@@ -20,8 +20,6 @@ import unittest
 
 import omni.usd
 
-from omni.isaac.lab.envs import ManagerBasedRLEnvCfg
-
 import omni.isaac.lab_tasks  # noqa: F401
 from omni.isaac.lab_tasks.utils import parse_env_cfg
 
@@ -60,7 +58,7 @@ class TestRecordVideoWrapper(unittest.TestCase):
                 omni.usd.get_context().new_stage()
 
                 # parse configuration
-                env_cfg: ManagerBasedRLEnvCfg = parse_env_cfg(task_name, device=self.device, num_envs=self.num_envs)
+                env_cfg = parse_env_cfg(task_name, device=self.device, num_envs=self.num_envs)
 
                 # create environment
                 env = gym.make(task_name, cfg=env_cfg, render_mode="rgb_array")

source/extensions/omni.isaac.lab_tasks/test/wrappers/test_rl_games_wrapper.py

@@ -20,8 +20,6 @@ import unittest
 
 import omni.usd
 
-from omni.isaac.lab.envs import ManagerBasedRLEnvCfg
-
 import omni.isaac.lab_tasks  # noqa: F401
 from omni.isaac.lab_tasks.utils.parse_cfg import load_cfg_from_registry, parse_env_cfg
 from omni.isaac.lab_tasks.utils.wrappers.rl_games import RlGamesVecEnvWrapper
@@ -58,7 +56,7 @@ class TestRlGamesVecEnvWrapper(unittest.TestCase):
                 # create a new stage
                 omni.usd.get_context().new_stage()
                 # parse configuration
-                env_cfg: ManagerBasedRLEnvCfg = parse_env_cfg(task_name, device=self.device, num_envs=self.num_envs)
+                env_cfg = parse_env_cfg(task_name, device=self.device, num_envs=self.num_envs)
                 agent_cfg = load_cfg_from_registry(task_name, "rl_games_cfg_entry_point")  # noqa: F841
                 # create environment
                 env = gym.make(task_name, cfg=env_cfg)

source/extensions/omni.isaac.lab_tasks/test/wrappers/test_rsl_rl_wrapper.py

@@ -20,8 +20,6 @@ import unittest
 
 import omni.usd
 
-from omni.isaac.lab.envs import ManagerBasedRLEnvCfg
-
 import omni.isaac.lab_tasks  # noqa: F401
 from omni.isaac.lab_tasks.utils.parse_cfg import load_cfg_from_registry, parse_env_cfg
 from omni.isaac.lab_tasks.utils.wrappers.rsl_rl import RslRlVecEnvWrapper
@@ -58,7 +56,7 @@ class TestRslRlVecEnvWrapper(unittest.TestCase):
                 # create a new stage
                 omni.usd.get_context().new_stage()
                 # parse configuration
-                env_cfg: ManagerBasedRLEnvCfg = parse_env_cfg(task_name, device=self.device, num_envs=self.num_envs)
+                env_cfg = parse_env_cfg(task_name, device=self.device, num_envs=self.num_envs)
                 agent_cfg = load_cfg_from_registry(task_name, "rsl_rl_cfg_entry_point")  # noqa: F841
                 # create environment
                 env = gym.make(task_name, cfg=env_cfg)
@@ -94,7 +92,7 @@ class TestRslRlVecEnvWrapper(unittest.TestCase):
                 # create a new stage
                 omni.usd.get_context().new_stage()
                 # parse configuration
-                env_cfg: ManagerBasedRLEnvCfg = parse_env_cfg(task_name, device=self.device, num_envs=self.num_envs)
+                env_cfg = parse_env_cfg(task_name, device=self.device, num_envs=self.num_envs)
                 # change to finite horizon
                 env_cfg.is_finite_horizon = True
 

source/extensions/omni.isaac.lab_tasks/test/wrappers/test_sb3_wrapper.py

@@ -21,8 +21,6 @@ import unittest
 
 import omni.usd
 
-from omni.isaac.lab.envs import ManagerBasedRLEnvCfg
-
 import omni.isaac.lab_tasks  # noqa: F401
 from omni.isaac.lab_tasks.utils.parse_cfg import load_cfg_from_registry, parse_env_cfg
 from omni.isaac.lab_tasks.utils.wrappers.sb3 import Sb3VecEnvWrapper
@@ -59,7 +57,7 @@ class TestStableBaselines3VecEnvWrapper(unittest.TestCase):
                 # create a new stage
                 omni.usd.get_context().new_stage()
                 # parse configuration
-                env_cfg: ManagerBasedRLEnvCfg = parse_env_cfg(task_name, device=self.device, num_envs=self.num_envs)
+                env_cfg = parse_env_cfg(task_name, device=self.device, num_envs=self.num_envs)
                 agent_cfg = load_cfg_from_registry(task_name, "sb3_cfg_entry_point")  # noqa: F841
                 # create environment
                 env = gym.make(task_name, cfg=env_cfg)

source/extensions/omni.isaac.lab_tasks/test/wrappers/test_skrl_wrapper.py

@@ -20,8 +20,6 @@ import unittest
 
 import omni.usd
 
-from omni.isaac.lab.envs import ManagerBasedRLEnvCfg
-
 import omni.isaac.lab_tasks  # noqa: F401
 from omni.isaac.lab_tasks.utils.parse_cfg import load_cfg_from_registry, parse_env_cfg
 from omni.isaac.lab_tasks.utils.wrappers.skrl import SkrlVecEnvWrapper
@@ -58,7 +56,7 @@ class TestSKRLVecEnvWrapper(unittest.TestCase):
                 # create a new stage
                 omni.usd.get_context().new_stage()
                 # parse configuration
-                env_cfg: ManagerBasedRLEnvCfg = parse_env_cfg(task_name, device=self.device, num_envs=self.num_envs)
+                env_cfg = parse_env_cfg(task_name, device=self.device, num_envs=self.num_envs)
                 agent_cfg = load_cfg_from_registry(task_name, "skrl_cfg_entry_point")  # noqa: F841
                 # create environment
                 env = gym.make(task_name, cfg=env_cfg)