Scene Design

Scenes manage collections of assets that define the physical environment for simulation. They provide a unified interface for composing backgrounds, objects, and interactive elements.

Core Architecture

Scenes use the Scene class that manages asset collections:

class Scene:
    def __init__(self, assets: list[Asset] | None = None):
        self.assets: dict[str, Asset] = {}

    def add_asset(self, asset: Asset):
        """Add single asset to scene."""
        self.assets[asset.name] = asset

    def get_scene_cfg(self) -> Any:
        """Generate Isaac Lab scene configuration from assets."""

Scenes automatically aggregate asset configurations into Isaac Lab-compatible scene configurations while maintaining asset relationships and spatial organization.

Scenes in Detail

The main method in the scene class is get_scene_cfg which returns a configclass containing all the scene elements.

It reads all the registered assets and their cfgs and combines them into a configclass.

def get_scene_cfg(self) -> Any:
      """Returns a configclass containing all the scene elements."""
      # Combine the configs into a configclass.
      fields: list[tuple[str, type, AssetCfg]] = []
      for asset in self.assets.values():
            fields.append((asset.name, type(asset.object_cfg), asset.object_cfg))
      NewConfigClass = make_configclass("SceneCfg", fields)
      new_config_class = NewConfigClass()
      return new_config_class

Environment Integration

# Asset creation and positioning
background = asset_registry.get_asset_by_name("kitchen")()
pick_object = asset_registry.get_asset_by_name("cracker_box")()
pick_object.set_initial_pose(Pose(position_xyz=(0.4, 0.0, 0.1)))

# Scene composition
scene = Scene(assets=[background, pick_object])

# Environment integration
environment = IsaacLabArenaEnvironment(
    name="manipulation_task",
    embodiment=embodiment,
    scene=scene,  # Physical environment layout
    task=task,
    teleop_device=teleop_device
)

Usage Examples

Kitchen Pick and Place

background = asset_registry.get_asset_by_name("kitchen")()
mustard_bottle = asset_registry.get_asset_by_name("mustard_bottle")()
mustard_bottle.set_initial_pose(Pose(position_xyz=(0.4, 0.0, 0.1)))

scene = Scene(assets=[background, mustard_bottle])

Microwave Interaction

kitchen = asset_registry.get_asset_by_name("kitchen")()
microwave = asset_registry.get_asset_by_name("microwave")()
microwave.set_initial_pose(Pose(position_xyz=(0.8, 0.0, 0.23)))

scene = Scene(assets=[kitchen, microwave])

Object References

# Reference elements within larger scene assets
destination = ObjectReference(
    name="kitchen_drawer",
    prim_path="{ENV_REGEX_NS}/kitchen/Cabinet_B_02",
    parent_asset=kitchen,
    object_type=ObjectType.RIGID
)

scene = Scene(assets=[kitchen, destination])