Creates a minimal function to change prim properties

source/isaaclab/isaaclab/markers/visualization_markers.py

@@ -24,7 +24,6 @@
 import torch
 from dataclasses import MISSING
 
-import omni.kit.commands
 import omni.physx.scripts.utils as physx_utils
 from pxr import Gf, PhysxSchema, Sdf, Usd, UsdGeom, UsdPhysics, Vt
 
@@ -396,18 +395,12 @@ def _process_prototype_prim(self, prim: Usd.Prim):
                 child_prim.SetInstanceable(False)
             # check if prim is a mesh -> if so, make it invisible to secondary rays
             if child_prim.IsA(UsdGeom.Gprim):
-                # early attach stage to usd context if stage is in memory
-                # since stage in memory is not supported by the "ChangePropertyCommand" kit command
-                sim_utils.attach_stage_to_usd_context(attaching_early=True)
-
                 # invisible to secondary rays such as depth images
-                omni.kit.commands.execute(
-                    "ChangePropertyCommand",
-                    prop_path=Sdf.Path(f"{child_prim.GetPrimPath().pathString}.primvars:invisibleToSecondaryRays"),
+                sim_utils.change_prim_property(
+                    prop_path=f"{child_prim.GetPrimPath().pathString}.primvars:invisibleToSecondaryRays",
                     value=True,
-                    prev=None,
+                    stage=prim.GetStage(),
                     type_to_create_if_not_exist=Sdf.ValueTypeNames.Bool,
-                    usd_context_name=prim.GetStage(),
                 )
             # add children to list
             all_prims += child_prim.GetChildren()

source/isaaclab/isaaclab/sim/spawners/from_files/from_files.py

@@ -16,11 +16,11 @@
     add_labels,
     bind_physics_material,
     bind_visual_material,
+    change_prim_property,
     clone,
     create_prim,
     get_current_stage,
     get_first_matching_child_prim,
-    is_current_stage_in_memory,
     select_usd_variants,
     set_prim_visibility,
 )
@@ -230,25 +230,13 @@ def spawn_ground_plane(
     # Change the color of the plane
     # Warning: This is specific to the default grid plane asset.
     if cfg.color is not None:
-        # avoiding this step if stage is in memory since the "ChangePropertyCommand" kit command
-        # is not supported in stage in memory
-        if is_current_stage_in_memory():
-            logger.warning(
-                "Ground plane color modification is not supported while the stage is in memory. Skipping operation."
-            )
-
-        else:
-            prop_path = f"{prim_path}/Looks/theGrid/Shader.inputs:diffuse_tint"
-
-            # change the color
-            omni.kit.commands.execute(
-                "ChangePropertyCommand",
-                prop_path=Sdf.Path(prop_path),
-                value=Gf.Vec3f(*cfg.color),
-                prev=None,
-                type_to_create_if_not_exist=Sdf.ValueTypeNames.Color3f,
-                usd_context_name=stage,
-            )
+        # change the color
+        change_prim_property(
+            prop_path=f"{prim_path}/Looks/theGrid/Shader.inputs:diffuse_tint",
+            value=Gf.Vec3f(*cfg.color),
+            stage=stage,
+            type_to_create_if_not_exist=Sdf.ValueTypeNames.Color3f,
+        )
     # Remove the light from the ground plane
     # It isn't bright enough and messes up with the user's lighting settings
     omni.kit.commands.execute("ToggleVisibilitySelectedPrims", selected_paths=[f"{prim_path}/SphereLight"], stage=stage)

source/isaaclab/isaaclab/sim/spawners/materials/visual_materials.py

@@ -59,14 +59,18 @@ def spawn_preview_surface(prim_path: str, cfg: visual_materials_cfg.PreviewSurfa
         # since stage in memory is not supported by the "CreatePreviewSurfaceMaterialPrim" kit command
         attach_stage_to_usd_context(attaching_early=True)
 
+        # note: this command does not support passing 'stage' as an argument
         omni.kit.commands.execute("CreatePreviewSurfaceMaterialPrim", mtl_path=prim_path, select_new_prim=False)
     else:
         raise ValueError(f"A prim already exists at path: '{prim_path}'.")
 
     # obtain prim
     prim = stage.GetPrimAtPath(f"{prim_path}/Shader")
+    # check prim is valid
+    if not prim.IsValid():
+        raise ValueError(f"Failed to create preview surface material at path: '{prim_path}'.")
     # apply properties
-    cfg = cfg.to_dict()
+    cfg = cfg.to_dict()  # type: ignore
     del cfg["func"]
     for attr_name, attr_value in cfg.items():
         safe_set_attribute_on_usd_prim(prim, f"inputs:{attr_name}", attr_value, camel_case=True)
@@ -108,23 +112,23 @@ def spawn_from_mdl_file(prim_path: str, cfg: visual_materials_cfg.MdlMaterialCfg
 
     # spawn material if it doesn't exist.
     if not stage.GetPrimAtPath(prim_path).IsValid():
-        # early attach stage to usd context if stage is in memory
-        # since stage in memory is not supported by the "CreateMdlMaterialPrim" kit command
-        attach_stage_to_usd_context(attaching_early=True)
-
         # extract material name from path
         material_name = cfg.mdl_path.split("/")[-1].split(".")[0]
         omni.kit.commands.execute(
             "CreateMdlMaterialPrim",
             mtl_url=cfg.mdl_path.format(NVIDIA_NUCLEUS_DIR=NVIDIA_NUCLEUS_DIR),
             mtl_name=material_name,
             mtl_path=prim_path,
+            stage=stage,
             select_new_prim=False,
         )
     else:
         raise ValueError(f"A prim already exists at path: '{prim_path}'.")
     # obtain prim
     prim = stage.GetPrimAtPath(f"{prim_path}/Shader")
+    # check prim is valid
+    if not prim.IsValid():
+        raise ValueError(f"Failed to create MDL material at path: '{prim_path}'.")
     # apply properties
     cfg = cfg.to_dict()
     del cfg["func"]

source/isaaclab/isaaclab/sim/spawners/sensors/sensors.py

@@ -8,10 +8,9 @@
 import logging
 from typing import TYPE_CHECKING
 
-import omni.kit.commands
 from pxr import Sdf, Usd
 
-from isaaclab.sim.utils import attach_stage_to_usd_context, clone, create_prim, get_current_stage
+from isaaclab.sim.utils import change_prim_property, clone, create_prim, get_current_stage
 from isaaclab.utils import to_camel_case
 
 if TYPE_CHECKING:
@@ -94,17 +93,11 @@ def spawn_camera(
 
     # lock camera from viewport (this disables viewport movement for camera)
     if cfg.lock_camera:
-        # early attach stage to usd context if stage is in memory
-        # since stage in memory is not supported by the "ChangePropertyCommand" kit command
-        attach_stage_to_usd_context(attaching_early=True)
-
-        omni.kit.commands.execute(
-            "ChangePropertyCommand",
-            prop_path=Sdf.Path(f"{prim_path}.omni:kit:cameraLock"),
+        change_prim_property(
+            prop_path=f"{prim_path}.omni:kit:cameraLock",
             value=True,
-            prev=None,
+            stage=stage,
             type_to_create_if_not_exist=Sdf.ValueTypeNames.Bool,
-            usd_context_name=stage,
         )
     # decide the custom attributes to add
     if cfg.projection_type == "pinhole":

source/isaaclab/isaaclab/sim/utils/prims.py

@@ -28,7 +28,7 @@
 
 from .queries import find_matching_prim_paths
 from .semantics import add_labels
-from .stage import attach_stage_to_usd_context, get_current_stage, get_current_stage_id
+from .stage import get_current_stage, get_current_stage_id
 from .transforms import convert_world_pose_to_local, standardize_xform_ops
 
 if TYPE_CHECKING:
@@ -384,21 +384,105 @@ def safe_set_attribute_on_usd_prim(prim: Usd.Prim, attr_name: str, value: Any, c
             f"Cannot set attribute '{attr_name}' with value '{value}'. Please modify the code to support this type."
         )
 
-    # early attach stage to usd context if stage is in memory
-    # since stage in memory is not supported by the "ChangePropertyCommand" kit command
-    attach_stage_to_usd_context(attaching_early=True)
-
-    # change property
-    omni.kit.commands.execute(
-        "ChangePropertyCommand",
-        prop_path=Sdf.Path(f"{prim.GetPath()}.{attr_name}"),
+    # change property using the change_prim_property function
+    change_prim_property(
+        prop_path=f"{prim.GetPath()}.{attr_name}",
         value=value,
-        prev=None,
+        stage=prim.GetStage(),
         type_to_create_if_not_exist=sdf_type,
-        usd_context_name=prim.GetStage(),
     )
 
 
+def change_prim_property(
+    prop_path: str | Sdf.Path,
+    value: Any,
+    stage: Usd.Stage | None = None,
+    type_to_create_if_not_exist: Sdf.ValueTypeNames | None = None,
+    is_custom: bool = False,
+) -> bool:
+    """Change or create a property value on a USD prim.
+
+    This is a simplified property setter that works with the current edit target. If you need
+    complex layer management, use :class:`omni.kit.commands.ChangePropertyCommand` instead.
+
+    By default, this function changes the value of the property when it exists. If the property
+    doesn't exist, :attr:`type_to_create_if_not_exist` must be provided to create it.
+
+    Note:
+        The attribute :attr:`value` must be the correct type for the property.
+        For example, if the property is a float, the value must be a float.
+        If it is supposed to be a RGB color, the value must be of type :class:`Gf.Vec3f`.
+
+    Args:
+        prop_path: Property path in the format ``/World/Prim.propertyName``.
+        value: Value to set. If None, the attribute value goes to its default value.
+            If the attribute has no default value, it is a silent no-op.
+        stage: The USD stage. Defaults to None, in which case the current stage is used.
+        type_to_create_if_not_exist: If not None and property doesn't exist, a new property will
+            be created with the given type and value. Defaults to None.
+        is_custom: If the property is created, specify if it is a custom property (not part of
+            the schema). Defaults to False.
+
+    Returns:
+        True if the property was successfully changed, False otherwise.
+
+    Raises:
+        ValueError: If the prim does not exist at the specified path.
+
+    Example:
+        >>> import isaaclab.sim as sim_utils
+        >>> from pxr import Sdf
+        >>>
+        >>> # Change an existing property
+        >>> sim_utils.change_prim_property(
+        ...     prop_path="/World/Cube.size",
+        ...     value=2.0
+        ... )
+        True
+        >>>
+        >>> # Create a new custom property
+        >>> sim_utils.change_prim_property(
+        ...     prop_path="/World/Cube.customValue",
+        ...     value=42,
+        ...     type_to_create_if_not_exist=Sdf.ValueTypeNames.Int,
+        ...     is_custom=True
+        ... )
+        True
+    """
+    # get stage handle
+    stage = get_current_stage() if stage is None else stage
+
+    # convert to Sdf.Path if needed
+    prop_path = Sdf.Path(prop_path) if isinstance(prop_path, str) else prop_path
+
+    # get the prim path
+    prim_path = prop_path.GetAbsoluteRootOrPrimPath()
+    prim = stage.GetPrimAtPath(prim_path)
+    if not prim or not prim.IsValid():
+        raise ValueError(f"Prim does not exist at path: '{prim_path}'")
+
+    # get or create the property
+    prop = stage.GetPropertyAtPath(prop_path)
+
+    if not prop:
+        if type_to_create_if_not_exist is not None:
+            # create new attribute on the prim
+            prop = prim.CreateAttribute(prop_path.name, type_to_create_if_not_exist, is_custom)
+        else:
+            logger.error(f"Property {prop_path} does not exist and 'type_to_create_if_not_exist' was not provided.")
+            return False
+
+    if not prop:
+        logger.error(f"Failed to get or create property at path: '{prop_path}'")
+        return False
+
+    # set the value
+    if value is None:
+        return bool(prop.Clear())
+    else:
+        return bool(prop.Set(value, Usd.TimeCode.Default()))
+
+
 """
 Exporting.
 """
@@ -853,19 +937,14 @@ def _add_reference_to_prim(prim: Usd.Prim) -> Usd.Prim:
     ret_val = get_metrics_assembler_interface().check_layers(
         stage.GetRootLayer().identifier, sdf_layer.identifier, stage_id
     )
+    # log that metric assembler did not detect any issues
     if ret_val["ret_val"]:
-        try:
-            import omni.metrics.assembler.ui
-
-            omni.kit.commands.execute(
-                "AddReference", stage=stage, prim_path=prim.GetPath(), reference=Sdf.Reference(usd_path)
-            )
-
-            return prim
-        except Exception:
-            return _add_reference_to_prim(prim)
-    else:
-        return _add_reference_to_prim(prim)
+        logger.info(
+            "Metric assembler detected no issues between the current stage and the referenced USD file at path:"
+            f" {usd_path}"
+        )
+    # add reference to the prim
+    return _add_reference_to_prim(prim)
 
 
 def get_usd_references(prim_path: str, stage: Usd.Stage | None = None) -> list[str]: