[WIP] Adds MJCF spawner

source/extensions/omni.isaac.lab/omni/isaac/lab/sim/spawners/from_files/__init__.py

@@ -13,5 +13,5 @@
 
 """
 
-from .from_files import spawn_from_urdf, spawn_from_usd, spawn_ground_plane
-from .from_files_cfg import GroundPlaneCfg, UrdfFileCfg, UsdFileCfg
+from .from_files import spawn_from_urdf, spawn_from_mjcf, spawn_from_usd, spawn_ground_plane
+from .from_files_cfg import GroundPlaneCfg, UrdfFileCfg, MjcfFileCfg, UsdFileCfg

source/extensions/omni.isaac.lab/omni/isaac/lab/sim/spawners/from_files/from_files.py

@@ -101,6 +101,46 @@ def spawn_from_urdf(
     # spawn asset from the generated usd file
     return _spawn_from_usd_file(prim_path, urdf_loader.usd_path, cfg, translation, orientation)
 
+@clone
+def spawn_from_mjcf(
+    prim_path: str,
+    cfg: from_files_cfg.MjcfFileCfg,
+    translation: tuple[float, float, float] | None = None,
+    orientation: tuple[float, float, float, float] | None = None,
+) -> Usd.Prim:
+    """Spawn an asset from a MJCF file and override the settings with the given config.
+
+    It uses the :class:`MjcfConverter` class to create a USD file from MJCF. This file is then imported
+    at the specified prim path.
+
+    In case a prim already exists at the given prim path, then the function does not create a new prim
+    or throw an error that the prim already exists. Instead, it just takes the existing prim and overrides
+    the settings with the given config.
+
+    .. note::
+        This function is decorated with :func:`clone` that resolves prim path into list of paths
+        if the input prim path is a regex pattern. This is done to support spawning multiple assets
+        from a single and cloning the USD prim at the given path expression.
+
+    Args:
+        prim_path: The prim path or pattern to spawn the asset at. If the prim path is a regex pattern,
+            then the asset is spawned at all the matching prim paths.
+        cfg: The configuration instance.
+        translation: The translation to apply to the prim w.r.t. its parent prim. Defaults to None, in which
+            case the translation specified in the generated USD file is used.
+        orientation: The orientation in (w, x, y, z) to apply to the prim w.r.t. its parent prim. Defaults to None,
+            in which case the orientation specified in the generated USD file is used.
+
+    Returns:
+        The prim of the spawned asset.
+
+    Raises:
+        FileNotFoundError: If the MJCF file does not exist at the given path.
+    """
+    # mjcf loader to convert mjcf to usd
+    mjcf_loader = converters.MjcfConverter(cfg)
+    # spawn asset from the generated usd file
+    return _spawn_from_usd_file(prim_path, mjcf_loader.usd_path, cfg, translation, orientation)
 
 def spawn_ground_plane(
     prim_path: str,

source/extensions/omni.isaac.lab/omni/isaac/lab/sim/spawners/from_files/from_files_cfg.py

@@ -121,6 +121,27 @@ class UrdfFileCfg(FileCfg, converters.UrdfConverterCfg):
 
     func: Callable = from_files.spawn_from_urdf
 
+@configclass
+class MjcfFileCfg(FileCfg, converters.MjcfConverterCfg):
+    """MJCF file to spawn asset from.
+
+    It uses the :class:`MjcfConverter` class to create a USD file from MJCF and spawns the imported
+    USD file. Similar to the :class:`UsdFileCfg`, the generated USD file can be modified by specifying
+    the respective properties in the configuration class.
+
+    See :meth:`spawn_from_mjcf` for more information.
+
+    .. note::
+        The configuration parameters include various properties. If not `None`, these properties
+        are modified on the spawned prim in a nested manner.
+
+        If they are set to a value, then the properties are modified on the spawned prim in a nested manner.
+        This is done by calling the respective function with the specified properties.
+
+    """
+
+    func: Callable = from_files.spawn_from_mjcf
+
 
 """
 Spawning ground plane.