# Copyright (c) 2022-2024, The ORBIT Project Developers.
# All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause
import builtins
import torch
from collections.abc import Sequence
from typing import Any
import carb
import omni.usd
from omni.isaac.cloner import GridCloner
from omni.isaac.core.prims import XFormPrimView
from pxr import PhysxSchema
import omni.isaac.orbit.sim as sim_utils
from omni.isaac.orbit.assets import Articulation, ArticulationCfg, AssetBaseCfg, RigidObject, RigidObjectCfg
from omni.isaac.orbit.sensors import ContactSensorCfg, FrameTransformerCfg, SensorBase, SensorBaseCfg
from omni.isaac.orbit.terrains import TerrainImporter, TerrainImporterCfg
from .interactive_scene_cfg import InteractiveSceneCfg
[docs]class InteractiveScene:
"""A scene that contains entities added to the simulation.
The interactive scene parses the :class:`InteractiveSceneCfg` class to create the scene.
Based on the specified number of environments, it clones the entities and groups them into different
categories (e.g., articulations, sensors, etc.).
Each entity is registered to scene based on its name in the configuration class. For example, if the user
specifies a robot in the configuration class as follows:
.. code-block:: python
from omni.isaac.orbit.scene import InteractiveSceneCfg
from omni.isaac.orbit.utils import configclass
from omni.isaac.orbit_assets.anymal import ANYMAL_C_CFG
@configclass
class MySceneCfg(InteractiveSceneCfg):
robot = ANYMAL_C_CFG.replace(prim_path="{ENV_REGEX_NS}/Robot")
Then the robot can be accessed from the scene as follows:
.. code-block:: python
from omni.isaac.orbit.scene import InteractiveScene
# create 128 environments
scene = InteractiveScene(cfg=MySceneCfg(num_envs=128))
# access the robot from the scene
robot = scene["robot"]
# access the robot based on its type
robot = scene.articulations["robot"]
.. note::
It is important to note that the scene only performs common operations on the entities. For example,
resetting the internal buffers, writing the buffers to the simulation and updating the buffers from the
simulation. The scene does not perform any task specific to the entity. For example, it does not apply
actions to the robot or compute observations from the robot. These tasks are handled by different
modules called "managers" in the framework. Please refer to the :mod:`omni.isaac.orbit.managers` sub-package
for more details.
"""
[docs] def __init__(self, cfg: InteractiveSceneCfg):
"""Initializes the scene.
Args:
cfg: The configuration class for the scene.
"""
# store inputs
self.cfg = cfg
# initialize scene elements
self._terrain = None
self._articulations = dict()
self._rigid_objects = dict()
self._sensors = dict()
self._extras = dict()
# obtain the current stage
self.stage = omni.usd.get_context().get_stage()
# prepare cloner for environment replication
self.cloner = GridCloner(spacing=self.cfg.env_spacing)
self.cloner.define_base_env(self.env_ns)
self.env_prim_paths = self.cloner.generate_paths(f"{self.env_ns}/env", self.cfg.num_envs)
# create source prim
self.stage.DefinePrim(self.env_prim_paths[0], "Xform")
# clone the env xform
env_origins = self.cloner.clone(
source_prim_path=self.env_prim_paths[0],
prim_paths=self.env_prim_paths,
replicate_physics=False,
copy_from_source=True,
)
self._default_env_origins = torch.tensor(env_origins, device=self.device, dtype=torch.float32)
# add entities from config
self._add_entities_from_cfg()
# replicate physics if we have more than one environment
# this is done to make scene initialization faster at play time
if self.cfg.replicate_physics and self.cfg.num_envs > 1:
self.cloner.replicate_physics(
source_prim_path=self.env_prim_paths[0],
prim_paths=self.env_prim_paths,
base_env_path=self.env_ns,
root_path=self.env_regex_ns.replace(".*", ""),
)
# obtain the current physics scene
physics_scene_prim_path = None
for prim in self.stage.Traverse():
if prim.HasAPI(PhysxSchema.PhysxSceneAPI):
physics_scene_prim_path = prim.GetPrimPath()
carb.log_info(f"Physics scene prim path: {physics_scene_prim_path}")
break
# filter collisions within each environment instance
self.cloner.filter_collisions(
physics_scene_prim_path,
"/World/collisions",
self.env_prim_paths,
global_paths=self._global_prim_paths,
)
def __str__(self) -> str:
"""Returns a string representation of the scene."""
msg = f"<class {self.__class__.__name__}>\n"
msg += f"\tNumber of environments: {self.cfg.num_envs}\n"
msg += f"\tEnvironment spacing : {self.cfg.env_spacing}\n"
msg += f"\tSource prim name : {self.env_prim_paths[0]}\n"
msg += f"\tGlobal prim paths : {self._global_prim_paths}\n"
msg += f"\tReplicate physics : {self.cfg.replicate_physics}"
return msg
"""
Properties.
"""
@property
def physics_dt(self) -> float:
"""The physics timestep of the scene."""
return sim_utils.SimulationContext.instance().get_physics_dt() # pyright: ignore [reportOptionalMemberAccess]
@property
def device(self) -> str:
"""The device on which the scene is created."""
return sim_utils.SimulationContext.instance().device # pyright: ignore [reportOptionalMemberAccess]
@property
def env_ns(self) -> str:
"""The namespace ``/World/envs`` in which all environments created.
The environments are present w.r.t. this namespace under "env_{N}" prim,
where N is a natural number.
"""
return "/World/envs"
@property
def env_regex_ns(self) -> str:
"""The namespace ``/World/envs/env_.*`` in which all environments created."""
return f"{self.env_ns}/env_.*"
@property
def num_envs(self) -> int:
"""The number of environments handled by the scene."""
return self.cfg.num_envs
@property
def env_origins(self) -> torch.Tensor:
"""The origins of the environments in the scene. Shape is (num_envs, 3)."""
if self._terrain is not None:
return self._terrain.env_origins
else:
return self._default_env_origins
@property
def terrain(self) -> TerrainImporter | None:
"""The terrain in the scene. If None, then the scene has no terrain.
Note:
We treat terrain separate from :attr:`extras` since terrains define environment origins and are
handled differently from other miscellaneous entities.
"""
return self._terrain
@property
def articulations(self) -> dict[str, Articulation]:
"""A dictionary of articulations in the scene."""
return self._articulations
@property
def rigid_objects(self) -> dict[str, RigidObject]:
"""A dictionary of rigid objects in the scene."""
return self._rigid_objects
@property
def sensors(self) -> dict[str, SensorBase]:
"""A dictionary of the sensors in the scene, such as cameras and contact reporters."""
return self._sensors
@property
def extras(self) -> dict[str, XFormPrimView]:
"""A dictionary of miscellaneous simulation objects that neither inherit from assets nor sensors.
The keys are the names of the miscellaneous objects, and the values are the `XFormPrimView`_
of the corresponding prims.
As an example, lights or other props in the scene that do not have any attributes or properties that you
want to alter at runtime can be added to this dictionary.
Note:
These are not reset or updated by the scene. They are mainly other prims that are not necessarily
handled by the interactive scene, but are useful to be accessed by the user.
.. _XFormPrimView: https://docs.omniverse.nvidia.com/py/isaacsim/source/extensions/omni.isaac.core/docs/index.html#omni.isaac.core.prims.XFormPrimView
"""
return self._extras
"""
Operations.
"""
[docs] def reset(self, env_ids: Sequence[int] | None = None):
"""Resets the scene entities.
Args:
env_ids: The indices of the environments to reset.
Defaults to None (all instances).
"""
# -- assets
for articulation in self._articulations.values():
articulation.reset(env_ids)
for rigid_object in self._rigid_objects.values():
rigid_object.reset(env_ids)
# -- sensors
for sensor in self._sensors.values():
sensor.reset(env_ids)
# -- flush physics sim view if called in extension mode
# this is needed when using PhysX GPU pipeline since the data needs to be sent to the underlying
# PhysX buffers that might live on a separate device
# note: In standalone mode, this method is called in the `step()` method of the simulation context.
# So we only need to flush when running in extension mode.
if builtins.ISAAC_LAUNCHED_FROM_TERMINAL:
sim_utils.SimulationContext.instance().physics_sim_view.flush() # pyright: ignore [reportOptionalMemberAccess]
[docs] def write_data_to_sim(self):
"""Writes the data of the scene entities to the simulation."""
# -- assets
for articulation in self._articulations.values():
articulation.write_data_to_sim()
for rigid_object in self._rigid_objects.values():
rigid_object.write_data_to_sim()
# -- flush physics sim view if called in extension mode
# this is needed when using PhysX GPU pipeline since the data needs to be sent to the underlying
# PhysX buffers that might live on a separate device
# note: In standalone mode, this method is called in the `step()` method of the simulation context.
# So we only need to flush when running in extension mode.
if builtins.ISAAC_LAUNCHED_FROM_TERMINAL:
sim_utils.SimulationContext.instance().physics_sim_view.flush() # pyright: ignore [reportOptionalMemberAccess]
[docs] def update(self, dt: float) -> None:
"""Update the scene entities.
Args:
dt: The amount of time passed from last :meth:`update` call.
"""
# -- assets
for articulation in self._articulations.values():
articulation.update(dt)
for rigid_object in self._rigid_objects.values():
rigid_object.update(dt)
# -- sensors
for sensor in self._sensors.values():
sensor.update(dt, force_recompute=not self.cfg.lazy_sensor_update)
"""
Operations: Iteration.
"""
[docs] def keys(self) -> list[str]:
"""Returns the keys of the scene entities.
Returns:
The keys of the scene entities.
"""
all_keys = ["terrain"]
for asset_family in [self._articulations, self._rigid_objects, self._sensors, self._extras]:
all_keys += list(asset_family.keys())
return all_keys
def __getitem__(self, key: str) -> Any:
"""Returns the scene entity with the given key.
Args:
key: The key of the scene entity.
Returns:
The scene entity.
"""
# check if it is a terrain
if key == "terrain":
return self._terrain
all_keys = ["terrain"]
# check if it is in other dictionaries
for asset_family in [self._articulations, self._rigid_objects, self._sensors, self._extras]:
out = asset_family.get(key)
# if found, return
if out is not None:
return out
all_keys += list(asset_family.keys())
# if not found, raise error
raise KeyError(f"Scene entity with key '{key}' not found. Available Entities: '{all_keys}'")
"""
Internal methods.
"""
def _add_entities_from_cfg(self):
"""Add scene entities from the config."""
# store paths that are in global collision filter
self._global_prim_paths = list()
# parse the entire scene config and resolve regex
for asset_name, asset_cfg in self.cfg.__dict__.items():
# skip keywords
# note: easier than writing a list of keywords: [num_envs, env_spacing, lazy_sensor_update]
if asset_name in InteractiveSceneCfg.__dataclass_fields__ or asset_cfg is None:
continue
# resolve regex
asset_cfg.prim_path = asset_cfg.prim_path.format(ENV_REGEX_NS=self.env_regex_ns)
# create asset
if isinstance(asset_cfg, TerrainImporterCfg):
# terrains are special entities since they define environment origins
asset_cfg.num_envs = self.cfg.num_envs
asset_cfg.env_spacing = self.cfg.env_spacing
self._terrain = asset_cfg.class_type(asset_cfg)
elif isinstance(asset_cfg, ArticulationCfg):
self._articulations[asset_name] = asset_cfg.class_type(asset_cfg)
elif isinstance(asset_cfg, RigidObjectCfg):
self._rigid_objects[asset_name] = asset_cfg.class_type(asset_cfg)
elif isinstance(asset_cfg, SensorBaseCfg):
# Update target frame path(s)' regex name space for FrameTransformer
if isinstance(asset_cfg, FrameTransformerCfg):
updated_target_frames = []
for target_frame in asset_cfg.target_frames:
target_frame.prim_path = target_frame.prim_path.format(ENV_REGEX_NS=self.env_regex_ns)
updated_target_frames.append(target_frame)
asset_cfg.target_frames = updated_target_frames
elif isinstance(asset_cfg, ContactSensorCfg):
updated_filter_prim_paths_expr = []
for filter_prim_path in asset_cfg.filter_prim_paths_expr:
updated_filter_prim_paths_expr.append(filter_prim_path.format(ENV_REGEX_NS=self.env_regex_ns))
asset_cfg.filter_prim_paths_expr = updated_filter_prim_paths_expr
self._sensors[asset_name] = asset_cfg.class_type(asset_cfg)
elif isinstance(asset_cfg, AssetBaseCfg):
# manually spawn asset
if asset_cfg.spawn is not None:
asset_cfg.spawn.func(
asset_cfg.prim_path,
asset_cfg.spawn,
translation=asset_cfg.init_state.pos,
orientation=asset_cfg.init_state.rot,
)
# store xform prim view corresponding to this asset
# all prims in the scene are Xform prims (i.e. have a transform component)
self._extras[asset_name] = XFormPrimView(asset_cfg.prim_path, reset_xform_properties=False)
else:
raise ValueError(f"Unknown asset config type for {asset_name}: {asset_cfg}")
# store global collision paths
if hasattr(asset_cfg, "collision_group") and asset_cfg.collision_group == -1:
asset_paths = sim_utils.find_matching_prim_paths(asset_cfg.prim_path)
self._global_prim_paths += asset_paths
