# Copyright (c) 2022-2026, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
# All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause
from __future__ import annotations
import logging
import warnings
import weakref
from typing import TYPE_CHECKING
import torch
import warp as wp
from isaaclab.assets.rigid_object_collection.base_rigid_object_collection_data import BaseRigidObjectCollectionData
from isaaclab.utils.buffers import TimestampedBufferWarp as TimestampedBuffer
from isaaclab.utils.math import normalize
from isaaclab.utils.warp import ProxyArray
from isaaclab_newton.assets import kernels as shared_kernels
from isaaclab_newton.physics import NewtonManager as SimulationManager
if TYPE_CHECKING:
from newton.selection import ArticulationView
# import logger
logger = logging.getLogger(__name__)
[docs]
class RigidObjectCollectionData(BaseRigidObjectCollectionData):
"""Data container for a rigid object collection.
This class contains the data for a rigid object collection in the simulation. The data includes the state of
all the bodies in the collection. The data is stored in the simulation world frame unless otherwise specified.
The data is in the order ``(num_instances, num_objects, data_size)``, where data_size is the size of the data.
For a rigid body, there are two frames of reference that are used:
- Actor frame: The frame of reference of the rigid body prim. This typically corresponds to the Xform prim
with the rigid body schema.
- Center of mass frame: The frame of reference of the center of mass of the rigid body.
Depending on the settings of the simulation, the actor frame and the center of mass frame may be the same.
This needs to be taken into account when interpreting the data.
The data is lazily updated, meaning that the data is only updated when it is accessed. This is useful
when the data is expensive to compute or retrieve. The data is updated when the timestamp of the buffer
is older than the current simulation timestamp. The timestamp is updated whenever the data is updated.
"""
__backend_name__: str = "newton"
"""The name of the backend for the rigid object collection data."""
def __init__(self, root_view: ArticulationView, num_bodies: int, device: str):
"""Initializes the rigid object collection data.
Args:
root_view: A single articulation view matching all body types across all environments.
The view's 2nd dimension (matches per world) corresponds to the body types.
num_bodies: The number of bodies in the collection.
device: The device used for processing.
"""
super().__init__(root_view, num_bodies, device)
self.num_bodies = num_bodies
# Store the view as a weak reference to avoid circular references
self._root_view: ArticulationView = weakref.proxy(root_view)
self.num_instances = self._root_view.count // num_bodies
# Set initial time stamp
self._sim_timestamp = 0.0
self._is_primed = False
# Convert gravity to direction vector
gravity = wp.to_torch(SimulationManager.get_model().gravity)[0]
gravity_dir = torch.tensor((gravity[0], gravity[1], gravity[2]), device=self.device)
gravity_dir = normalize(gravity_dir.unsqueeze(0)).squeeze(0)
# Initialize constants
self.GRAVITY_VEC_W = ProxyArray(
wp.from_torch(gravity_dir.repeat(self.num_instances, self.num_bodies, 1), dtype=wp.vec3f)
)
self.FORWARD_VEC_B = ProxyArray(
wp.from_torch(
torch.tensor((1.0, 0.0, 0.0), device=self.device).repeat(self.num_instances, self.num_bodies, 1),
dtype=wp.vec3f,
)
)
self._create_simulation_bindings()
self._create_buffers()
@property
def is_primed(self) -> bool:
"""Whether the rigid object collection data is fully instantiated and ready to use."""
return self._is_primed
@is_primed.setter
def is_primed(self, value: bool) -> None:
"""Set whether the rigid object collection data is fully instantiated and ready to use.
.. note::
Once this quantity is set to True, it cannot be changed.
Args:
value: The primed state.
Raises:
ValueError: If the rigid object collection data is already primed.
"""
if self._is_primed:
raise ValueError("The rigid object collection data is already primed.")
self._is_primed = value
[docs]
def update(self, dt: float) -> None:
"""Updates the data for the rigid object collection.
Args:
dt: The time step for the update. This must be a positive value.
"""
# update the simulation timestamp
self._sim_timestamp += dt
# Trigger an update of the body com acceleration buffer at a higher frequency
# since we do finite differencing.
self.body_com_acc_w
"""
Names.
"""
body_names: list[str] = None
"""Body names in the order parsed by the simulation view."""
"""
Defaults.
"""
@property
def default_body_pose(self) -> ProxyArray:
"""Default body pose ``[pos, quat]`` in local environment frame.
The position and quaternion are of the rigid body's actor frame.
Shape is (num_instances, num_bodies), dtype = wp.transformf. In torch this resolves to
(num_instances, num_bodies, 7).
"""
return self._default_body_pose_ta
@default_body_pose.setter
def default_body_pose(self, value: wp.array) -> None:
"""Set the default body pose.
Args:
value: The default body pose. Shape is (num_instances, num_bodies, 7).
Raises:
ValueError: If the rigid object collection data is already primed.
"""
if self._is_primed:
raise ValueError("The rigid object collection data is already primed.")
self._default_body_pose.assign(value)
@property
def default_body_vel(self) -> ProxyArray:
"""Default body velocity ``[lin_vel, ang_vel]`` in local environment frame.
The linear and angular velocities are of the rigid body's center of mass frame.
Shape is (num_instances, num_bodies), dtype = wp.spatial_vectorf. In torch this resolves to
(num_instances, num_bodies, 6).
"""
return self._default_body_vel_ta
@default_body_vel.setter
def default_body_vel(self, value: wp.array) -> None:
"""Set the default body velocity.
Args:
value: The default body velocity. Shape is (num_instances, num_bodies, 6).
Raises:
ValueError: If the rigid object collection data is already primed.
"""
if self._is_primed:
raise ValueError("The rigid object collection data is already primed.")
self._default_body_vel.assign(value)
"""
Body state properties.
"""
@property
def body_link_pose_w(self) -> ProxyArray:
"""Body link pose ``[pos, quat]`` in simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.transformf. In torch this resolves to
(num_instances, num_bodies, 7).
This quantity is the pose of the actor frame of the rigid body relative to the world.
The orientation is provided in (x, y, z, w) format.
"""
return self._body_link_pose_w_ta
@property
def body_link_vel_w(self) -> ProxyArray:
"""Body link velocity ``[lin_vel, ang_vel]`` in simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.spatial_vectorf. In torch this resolves to
(num_instances, num_bodies, 6).
This quantity contains the linear and angular velocities of the actor frame of the root
rigid body relative to the world.
"""
if self._body_link_vel_w.timestamp < self._sim_timestamp:
wp.launch(
shared_kernels.get_body_link_vel_from_body_com_vel,
dim=(self.num_instances, self.num_bodies),
inputs=[
self.body_com_vel_w.warp,
self.body_link_pose_w.warp,
self.body_com_pos_b.warp,
],
outputs=[
self._body_link_vel_w.data,
],
device=self.device,
)
self._body_link_vel_w.timestamp = self._sim_timestamp
return self._body_link_vel_w_ta
@property
def body_com_pose_w(self) -> ProxyArray:
"""Body center of mass pose ``[pos, quat]`` in simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.transformf. In torch this resolves to
(num_instances, num_bodies, 7).
This quantity is the pose of the center of mass frame of the rigid body relative to the world.
The orientation is provided in (x, y, z, w) format.
"""
if self._body_com_pose_w.timestamp < self._sim_timestamp:
wp.launch(
shared_kernels.get_body_com_pose_from_body_link_pose,
dim=(self.num_instances, self.num_bodies),
inputs=[
self.body_link_pose_w.warp,
self.body_com_pos_b.warp,
],
outputs=[
self._body_com_pose_w.data,
],
device=self.device,
)
self._body_com_pose_w.timestamp = self._sim_timestamp
return self._body_com_pose_w_ta
@property
def body_com_vel_w(self) -> ProxyArray:
"""Body center of mass velocity ``[lin_vel, ang_vel]`` in simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.spatial_vectorf. In torch this resolves to
(num_instances, num_bodies, 6).
This quantity contains the linear and angular velocities of the root rigid body's center of mass frame
relative to the world.
"""
return self._body_com_vel_w_ta
@property
def body_com_acc_w(self) -> ProxyArray:
"""Acceleration of all bodies ``[lin_acc, ang_acc]`` in the simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.spatial_vectorf. In torch this resolves to
(num_instances, num_bodies, 6).
This quantity is the acceleration of the rigid bodies' center of mass frame relative to the world.
"""
if self._body_com_acc_w.timestamp < self._sim_timestamp:
wp.launch(
shared_kernels.derive_body_acceleration_from_body_com_velocities,
dim=(self.num_instances, self.num_bodies),
device=self.device,
inputs=[
self.body_com_vel_w.warp,
SimulationManager.get_dt(),
self._previous_body_com_vel,
],
outputs=[
self._body_com_acc_w.data,
],
)
self._body_com_acc_w.timestamp = self._sim_timestamp
return self._body_com_acc_w_ta
@property
def body_com_pose_b(self) -> ProxyArray:
"""Center of mass pose ``[pos, quat]`` of all bodies in their respective body's link frames.
Shape is (num_instances, num_bodies), dtype = wp.transformf. In torch this resolves to
(num_instances, num_bodies, 7).
This quantity is the pose of the center of mass frame of the rigid body relative to the body's link frame.
The orientation is provided in (x, y, z, w) format.
"""
warnings.warn(
"In Newton, body com pose always has unit quaternion. Consider using body_com_pos_b instead."
"Querying this property requires appending a unit quaternion to the position which is expensive.",
category=UserWarning,
stacklevel=2,
)
if self._body_com_pose_b.timestamp < self._sim_timestamp:
wp.launch(
shared_kernels.make_dummy_body_com_pose_b,
dim=(self.num_instances, self.num_bodies),
inputs=[
self.body_com_pos_b.warp,
],
outputs=[
self._body_com_pose_b.data,
],
device=self.device,
)
self._body_com_pose_b.timestamp = self._sim_timestamp
return self._body_com_pose_b_ta
@property
def body_com_pos_b(self) -> ProxyArray:
"""Center of mass position of all of the bodies in their respective link frames.
Shape is (num_instances, num_bodies), dtype = wp.vec3f. In torch this resolves to
(num_instances, num_bodies, 3).
This quantity is the center of mass location relative to its body's link frame.
"""
return self._body_com_pos_b_ta
@property
def body_mass(self) -> ProxyArray:
"""Mass of all bodies in the simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.float32.
In torch this resolves to (num_instances, num_bodies).
"""
return self._body_mass_ta
@property
def body_inertia(self) -> ProxyArray:
"""Inertia of all bodies in the simulation world frame.
Shape is (num_instances, num_bodies, 9), dtype = wp.float32.
In torch this resolves to (num_instances, num_bodies, 9).
"""
return self._body_inertia_ta
"""
Derived Properties.
"""
@property
def projected_gravity_b(self) -> ProxyArray:
"""Projection of the gravity direction on base frame.
Shape is (num_instances, num_bodies), dtype = wp.vec3f. In torch this resolves to
(num_instances, num_bodies, 3).
"""
if self._projected_gravity_b.timestamp < self._sim_timestamp:
wp.launch(
shared_kernels.quat_apply_inverse_2D_kernel,
dim=(self.num_instances, self.num_bodies),
inputs=[self.GRAVITY_VEC_W.warp, self.body_link_quat_w.warp],
outputs=[self._projected_gravity_b.data],
device=self.device,
)
self._projected_gravity_b.timestamp = self._sim_timestamp
return self._projected_gravity_b_ta
@property
def heading_w(self) -> ProxyArray:
"""Yaw heading of the base frame (in radians).
Shape is (num_instances, num_bodies), dtype = wp.float32. In torch this resolves to (num_instances, num_bodies).
.. note::
This quantity is computed by assuming that the forward-direction of the base
frame is along x-direction, i.e. :math:`(1, 0, 0)`.
"""
if self._heading_w.timestamp < self._sim_timestamp:
wp.launch(
shared_kernels.body_heading_w,
dim=(self.num_instances, self.num_bodies),
inputs=[self.FORWARD_VEC_B.warp, self.body_link_quat_w.warp],
outputs=[self._heading_w.data],
device=self.device,
)
self._heading_w.timestamp = self._sim_timestamp
return self._heading_w_ta
@property
def body_link_lin_vel_b(self) -> ProxyArray:
"""Root link linear velocity in base frame.
Shape is (num_instances, num_bodies), dtype = wp.vec3f. In torch this resolves to
(num_instances, num_bodies, 3).
This quantity is the linear velocity of the actor frame of the root rigid body frame with respect to the
rigid body's actor frame.
"""
if self._body_link_lin_vel_b.timestamp < self._sim_timestamp:
wp.launch(
shared_kernels.quat_apply_inverse_2D_kernel,
dim=(self.num_instances, self.num_bodies),
inputs=[self.body_link_lin_vel_w.warp, self.body_link_quat_w.warp],
outputs=[self._body_link_lin_vel_b.data],
device=self.device,
)
self._body_link_lin_vel_b.timestamp = self._sim_timestamp
return self._body_link_lin_vel_b_ta
@property
def body_link_ang_vel_b(self) -> ProxyArray:
"""Root link angular velocity in base frame.
Shape is (num_instances, num_bodies), dtype = wp.vec3f. In torch this resolves to
(num_instances, num_bodies, 3).
This quantity is the angular velocity of the actor frame of the root rigid body frame with respect to the
rigid body's actor frame.
"""
if self._body_link_ang_vel_b.timestamp < self._sim_timestamp:
wp.launch(
shared_kernels.quat_apply_inverse_2D_kernel,
dim=(self.num_instances, self.num_bodies),
inputs=[self.body_link_ang_vel_w.warp, self.body_link_quat_w.warp],
outputs=[self._body_link_ang_vel_b.data],
device=self.device,
)
self._body_link_ang_vel_b.timestamp = self._sim_timestamp
return self._body_link_ang_vel_b_ta
@property
def body_com_lin_vel_b(self) -> ProxyArray:
"""Root center of mass linear velocity in base frame.
Shape is (num_instances, num_bodies), dtype = wp.vec3f. In torch this resolves to
(num_instances, num_bodies, 3).
This quantity is the linear velocity of the root rigid body's center of mass frame with respect to the
rigid body's actor frame.
"""
if self._body_com_lin_vel_b.timestamp < self._sim_timestamp:
wp.launch(
shared_kernels.quat_apply_inverse_2D_kernel,
dim=(self.num_instances, self.num_bodies),
inputs=[self.body_com_lin_vel_w.warp, self.body_link_quat_w.warp],
outputs=[self._body_com_lin_vel_b.data],
device=self.device,
)
self._body_com_lin_vel_b.timestamp = self._sim_timestamp
return self._body_com_lin_vel_b_ta
@property
def body_com_ang_vel_b(self) -> ProxyArray:
"""Root center of mass angular velocity in base frame.
Shape is (num_instances, num_bodies), dtype = wp.vec3f. In torch this resolves to
(num_instances, num_bodies, 3).
This quantity is the angular velocity of the root rigid body's center of mass frame with respect to the
rigid body's actor frame.
"""
if self._body_com_ang_vel_b.timestamp < self._sim_timestamp:
wp.launch(
shared_kernels.quat_apply_inverse_2D_kernel,
dim=(self.num_instances, self.num_bodies),
inputs=[self.body_com_ang_vel_w.warp, self.body_link_quat_w.warp],
outputs=[self._body_com_ang_vel_b.data],
device=self.device,
)
self._body_com_ang_vel_b.timestamp = self._sim_timestamp
return self._body_com_ang_vel_b_ta
"""
Sliced properties.
"""
@property
def body_link_pos_w(self) -> ProxyArray:
"""Positions of all bodies in simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.vec3f. In torch this resolves to
(num_instances, num_bodies, 3).
This quantity is the position of the rigid bodies' actor frame relative to the world.
"""
if self._body_link_pos_w_ta is None:
self._body_link_pos_w_ta = ProxyArray(self._get_pos_from_transform(self.body_link_pose_w.warp))
return self._body_link_pos_w_ta
@property
def body_link_quat_w(self) -> ProxyArray:
"""Orientation (x, y, z, w) of all bodies in simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.quatf. In torch this resolves to
(num_instances, num_bodies, 4).
This quantity is the orientation of the rigid bodies' actor frame relative to the world.
"""
if self._body_link_quat_w_ta is None:
self._body_link_quat_w_ta = ProxyArray(self._get_quat_from_transform(self.body_link_pose_w.warp))
return self._body_link_quat_w_ta
@property
def body_link_lin_vel_w(self) -> ProxyArray:
"""Linear velocity of all bodies in simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.vec3f. In torch this resolves to
(num_instances, num_bodies, 3).
This quantity is the linear velocity of the rigid bodies' actor frame relative to the world.
"""
if self._body_link_lin_vel_w_ta is None:
self._body_link_lin_vel_w_ta = ProxyArray(self._get_lin_vel_from_spatial_vector(self.body_link_vel_w.warp))
return self._body_link_lin_vel_w_ta
@property
def body_link_ang_vel_w(self) -> ProxyArray:
"""Angular velocity of all bodies in simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.vec3f. In torch this resolves to
(num_instances, num_bodies, 3).
This quantity is the angular velocity of the rigid bodies' actor frame relative to the world.
"""
if self._body_link_ang_vel_w_ta is None:
self._body_link_ang_vel_w_ta = ProxyArray(self._get_ang_vel_from_spatial_vector(self.body_link_vel_w.warp))
return self._body_link_ang_vel_w_ta
@property
def body_com_pos_w(self) -> ProxyArray:
"""Positions of all bodies' center of mass in simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.vec3f. In torch this resolves to
(num_instances, num_bodies, 3).
This quantity is the position of the rigid bodies' center of mass frame.
"""
if self._body_com_pos_w_ta is None:
self._body_com_pos_w_ta = ProxyArray(self._get_pos_from_transform(self.body_com_pose_w.warp))
return self._body_com_pos_w_ta
@property
def body_com_quat_w(self) -> ProxyArray:
"""Orientation (x, y, z, w) of the principal axes of inertia of all bodies in simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.quatf. In torch this resolves to
(num_instances, num_bodies, 4).
This quantity is the orientation of the principal axes of inertia of the rigid bodies.
"""
if self._body_com_quat_w_ta is None:
self._body_com_quat_w_ta = ProxyArray(self._get_quat_from_transform(self.body_com_pose_w.warp))
return self._body_com_quat_w_ta
@property
def body_com_lin_vel_w(self) -> ProxyArray:
"""Linear velocity of all bodies in simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.vec3f. In torch this resolves to
(num_instances, num_bodies, 3).
This quantity is the linear velocity of the rigid bodies' center of mass frame.
"""
if self._body_com_lin_vel_w_ta is None:
self._body_com_lin_vel_w_ta = ProxyArray(self._get_lin_vel_from_spatial_vector(self.body_com_vel_w.warp))
return self._body_com_lin_vel_w_ta
@property
def body_com_ang_vel_w(self) -> ProxyArray:
"""Angular velocity of all bodies in simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.vec3f. In torch this resolves to
(num_instances, num_bodies, 3).
This quantity is the angular velocity of the rigid bodies' center of mass frame.
"""
if self._body_com_ang_vel_w_ta is None:
self._body_com_ang_vel_w_ta = ProxyArray(self._get_ang_vel_from_spatial_vector(self.body_com_vel_w.warp))
return self._body_com_ang_vel_w_ta
@property
def body_com_lin_acc_w(self) -> ProxyArray:
"""Linear acceleration of all bodies in simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.vec3f. In torch this resolves to
(num_instances, num_bodies, 3).
This quantity is the linear acceleration of the rigid bodies' center of mass frame.
"""
if self._body_com_lin_acc_w_ta is None:
self._body_com_lin_acc_w_ta = ProxyArray(self._get_lin_vel_from_spatial_vector(self.body_com_acc_w.warp))
return self._body_com_lin_acc_w_ta
@property
def body_com_ang_acc_w(self) -> ProxyArray:
"""Angular acceleration of all bodies in simulation world frame.
Shape is (num_instances, num_bodies), dtype = wp.vec3f. In torch this resolves to
(num_instances, num_bodies, 3).
This quantity is the angular acceleration of the rigid bodies' center of mass frame.
"""
if self._body_com_ang_acc_w_ta is None:
self._body_com_ang_acc_w_ta = ProxyArray(self._get_ang_vel_from_spatial_vector(self.body_com_acc_w.warp))
return self._body_com_ang_acc_w_ta
@property
def body_com_quat_b(self) -> ProxyArray:
"""Orientation (x, y, z, w) of the principal axes of inertia of all of the bodies in their
respective link frames.
Shape is (num_instances, num_bodies), dtype = wp.quatf. In torch this resolves to
(num_instances, num_bodies, 4).
This quantity is the orientation of the principal axes of inertia relative to its body's link frame.
"""
if self._body_com_quat_b_ta is None:
self._body_com_quat_b_ta = ProxyArray(self._get_quat_from_transform(self.body_com_pose_b.warp))
return self._body_com_quat_b_ta
def _create_simulation_bindings(self) -> None:
"""Create simulation bindings for the body data.
For a rigid object collection in Newton, a single :class:`ArticulationView` matches all body
types. Its data is shaped ``(num_envs, num_bodies, ...)``, where the 2nd dimension (matches
per world) corresponds to the different body types. This gives us direct 2D bindings into
Newton's state with no scatter/gather overhead.
"""
state_0 = SimulationManager.get_state_0()
model = SimulationManager.get_model()
# Root transforms/velocities are (num_envs, num_bodies) — direct 2D bindings
self._sim_bind_body_link_pose_w = self._root_view.get_root_transforms(state_0)
self._sim_bind_body_com_vel_w = self._root_view.get_root_velocities(state_0)
# Attributes have a trailing link dim of 1: (num_envs, num_bodies, 1) -> [:, :, 0]
self._sim_bind_body_com_pos_b = self._root_view.get_attribute("body_com", model)[:, :, 0]
self._sim_bind_body_external_wrench = self._root_view.get_attribute("body_f", state_0)[:, :, 0]
# -- Body mass: (num_envs, num_bodies, 1) float32 → squeeze to (num_envs, num_bodies)
self._sim_bind_body_mass = self._root_view.get_attribute("body_mass", model)[:, :, 0]
# -- Body inertia: (num_envs, num_bodies, 1) mat33f → squeeze, reinterpret as (N, B, 9) float32.
# Each mat33f element is 9 contiguous float32 values (36 bytes), so the inner stride is 4.
# The slice may be non-contiguous in the outer dims, so we preserve those strides.
_body_inertia_raw = self._root_view.get_attribute("body_inertia", model)[:, :, 0]
self._body_inertia = wp.array(
ptr=_body_inertia_raw.ptr,
dtype=wp.float32,
shape=(self.num_instances, self.num_bodies, 9),
strides=(_body_inertia_raw.strides[0], _body_inertia_raw.strides[1], 4),
device=_body_inertia_raw.device,
copy=False,
)
# Re-pin ProxyArray wrappers to the newly created sim bindings.
# On first init, _create_buffers() handles this after all buffers exist.
if hasattr(self, "_body_link_pose_w_ta"):
self._pin_proxy_arrays()
def _create_buffers(self) -> None:
"""Create buffers for computing and caching derived quantities."""
super()._create_buffers()
# Initialize the lazy buffers.
# -- link frame w.r.t. world frame (computed from com vel)
self._body_link_vel_w = TimestampedBuffer(
(self.num_instances, self.num_bodies), self.device, wp.spatial_vectorf
)
# -- com frame w.r.t. link frame
self._body_com_pose_b = TimestampedBuffer((self.num_instances, self.num_bodies), self.device, wp.transformf)
# -- com frame w.r.t. world frame
self._body_com_pose_w = TimestampedBuffer((self.num_instances, self.num_bodies), self.device, wp.transformf)
self._body_com_acc_w = TimestampedBuffer((self.num_instances, self.num_bodies), self.device, wp.spatial_vectorf)
# -- combined state (these are cached as they concatenate)
self._body_state_w = TimestampedBuffer(
(self.num_instances, self.num_bodies), self.device, shared_kernels.vec13f
)
self._body_link_state_w = TimestampedBuffer(
(self.num_instances, self.num_bodies), self.device, shared_kernels.vec13f
)
self._body_com_state_w = TimestampedBuffer(
(self.num_instances, self.num_bodies), self.device, shared_kernels.vec13f
)
# -- Default state
self._default_body_pose = wp.zeros(
(self.num_instances, self.num_bodies), dtype=wp.transformf, device=self.device
)
self._default_body_vel = wp.zeros(
(self.num_instances, self.num_bodies), dtype=wp.spatial_vectorf, device=self.device
)
self._default_body_state = None
# -- Derived properties
self._projected_gravity_b = TimestampedBuffer((self.num_instances, self.num_bodies), self.device, wp.vec3f)
self._heading_w = TimestampedBuffer((self.num_instances, self.num_bodies), self.device, wp.float32)
self._body_link_lin_vel_b = TimestampedBuffer((self.num_instances, self.num_bodies), self.device, wp.vec3f)
self._body_link_ang_vel_b = TimestampedBuffer((self.num_instances, self.num_bodies), self.device, wp.vec3f)
self._body_com_lin_vel_b = TimestampedBuffer((self.num_instances, self.num_bodies), self.device, wp.vec3f)
self._body_com_ang_vel_b = TimestampedBuffer((self.num_instances, self.num_bodies), self.device, wp.vec3f)
# -- Initialize history for finite differencing
self._previous_body_com_vel = wp.clone(self._sim_bind_body_com_vel_w)
# Pin all ProxyArray wrappers to current buffers.
self._pin_proxy_arrays()
def _pin_proxy_arrays(self) -> None:
"""Create or rebind all pinned ProxyArray wrappers.
Called from :meth:`_create_buffers` on first initialization and from
:meth:`_create_simulation_bindings` after a full simulation reset when
the solver recreates its internal arrays.
"""
is_rebind = hasattr(self, "_body_link_pose_w_ta")
if is_rebind:
# Rebind sim-bound ProxyArrays to new solver arrays
self._body_link_pose_w_ta = ProxyArray(self._sim_bind_body_link_pose_w)
self._body_com_vel_w_ta = ProxyArray(self._sim_bind_body_com_vel_w)
self._body_com_pos_b_ta = ProxyArray(self._sim_bind_body_com_pos_b)
self._body_mass_ta = ProxyArray(self._sim_bind_body_mass)
self._body_inertia_ta = ProxyArray(self._body_inertia)
else:
# First-time creation: pin ProxyArrays to current buffers
# Category 1: sim-bound and pre-allocated buffers
# Newton wp.array pointers are stable, so a ProxyArray wrapping them is valid forever.
self._body_link_pose_w_ta = ProxyArray(self._sim_bind_body_link_pose_w)
self._body_com_vel_w_ta = ProxyArray(self._sim_bind_body_com_vel_w)
self._body_com_pos_b_ta = ProxyArray(self._sim_bind_body_com_pos_b)
self._body_mass_ta = ProxyArray(self._sim_bind_body_mass)
self._body_inertia_ta = ProxyArray(self._body_inertia)
self._default_body_pose_ta = ProxyArray(self._default_body_pose)
self._default_body_vel_ta = ProxyArray(self._default_body_vel)
# Category 2: TimestampedBuffer properties
self._body_link_vel_w_ta = ProxyArray(self._body_link_vel_w.data)
self._body_com_pose_w_ta = ProxyArray(self._body_com_pose_w.data)
self._body_com_acc_w_ta = ProxyArray(self._body_com_acc_w.data)
self._body_com_pose_b_ta = ProxyArray(self._body_com_pose_b.data)
self._projected_gravity_b_ta = ProxyArray(self._projected_gravity_b.data)
self._heading_w_ta = ProxyArray(self._heading_w.data)
self._body_link_lin_vel_b_ta = ProxyArray(self._body_link_lin_vel_b.data)
self._body_link_ang_vel_b_ta = ProxyArray(self._body_link_ang_vel_b.data)
self._body_com_lin_vel_b_ta = ProxyArray(self._body_com_lin_vel_b.data)
self._body_com_ang_vel_b_ta = ProxyArray(self._body_com_ang_vel_b.data)
self._body_state_w_ta = ProxyArray(self._body_state_w.data)
self._body_link_state_w_ta = ProxyArray(self._body_link_state_w.data)
self._body_com_state_w_ta = ProxyArray(self._body_com_state_w.data)
# -- deprecated state properties (lazy); type annotation declared once here
self._default_body_state_ta: ProxyArray | None = None
# Invalidate lazy sliced ProxyArrays AND their backing wp.arrays so they are
# re-created from fresh data on next access. On first init the backing fields
# are already None (set by _create_buffers), so the assignments below are
# harmless no-ops. On rebind they reset stale pointers into freed transform
# memory after a sim reset.
self._body_link_pos_w_ta: ProxyArray | None = None
self._body_link_quat_w_ta: ProxyArray | None = None
self._body_link_lin_vel_w_ta: ProxyArray | None = None
self._body_link_ang_vel_w_ta: ProxyArray | None = None
self._body_com_pos_w_ta: ProxyArray | None = None
self._body_com_quat_w_ta: ProxyArray | None = None
self._body_com_lin_vel_w_ta: ProxyArray | None = None
self._body_com_ang_vel_w_ta: ProxyArray | None = None
self._body_com_lin_acc_w_ta: ProxyArray | None = None
self._body_com_ang_acc_w_ta: ProxyArray | None = None
self._body_com_quat_b_ta: ProxyArray | None = None
self._default_body_state_ta: ProxyArray | None = None
self._default_body_state = None
"""
Helpers.
"""
def _get_pos_from_transform(self, transform: wp.array) -> wp.array:
"""Generates a position array from a transform array."""
return wp.array(
ptr=transform.ptr,
shape=transform.shape,
dtype=wp.vec3f,
strides=transform.strides,
device=self.device,
)
def _get_quat_from_transform(self, transform: wp.array) -> wp.array:
"""Generates a quaternion array from a transform array."""
return wp.array(
ptr=transform.ptr + 3 * 4,
shape=transform.shape,
dtype=wp.quatf,
strides=transform.strides,
device=self.device,
)
def _get_lin_vel_from_spatial_vector(self, spatial_vector: wp.array) -> wp.array:
"""Generates a linear velocity array from a spatial vector array."""
return wp.array(
ptr=spatial_vector.ptr,
shape=spatial_vector.shape,
dtype=wp.vec3f,
strides=spatial_vector.strides,
device=self.device,
)
def _get_ang_vel_from_spatial_vector(self, spatial_vector: wp.array) -> wp.array:
"""Generates an angular velocity array from a spatial vector array."""
return wp.array(
ptr=spatial_vector.ptr + 3 * 4,
shape=spatial_vector.shape,
dtype=wp.vec3f,
strides=spatial_vector.strides,
device=self.device,
)
"""
Deprecated properties.
"""
@property
def default_body_state(self) -> ProxyArray:
"""Default root state ``[pos, quat, lin_vel, ang_vel]`` in local environment frame.
The position and quaternion are of the rigid body's actor frame. Meanwhile, the linear and angular velocities
are of the center of mass frame. Shape is (num_instances, num_bodies, 13).
"""
warnings.warn(
"Reading the body state directly is deprecated since IsaacLab 3.0 and will be removed in a future version. "
"Please use the default_body_pose and default_body_vel properties instead.",
DeprecationWarning,
stacklevel=2,
)
if self._default_body_state is None:
self._default_body_state = wp.zeros(
(self.num_instances, self.num_bodies), dtype=shared_kernels.vec13f, device=self.device
)
self._default_body_state_ta = ProxyArray(self._default_body_state)
wp.launch(
shared_kernels.concat_body_pose_and_vel_to_state,
dim=(self.num_instances, self.num_bodies),
inputs=[
self._default_body_pose,
self._default_body_vel,
],
outputs=[
self._default_body_state,
],
device=self.device,
)
return self._default_body_state_ta
@property
def body_state_w(self) -> ProxyArray:
"""Deprecated, same as :attr:`body_link_pose_w` and :attr:`body_com_vel_w`."""
warnings.warn(
"The `body_state_w` property will be deprecated in IsaacLab 4.0. Please use `body_link_pose_w` and "
"`body_com_vel_w` instead.",
DeprecationWarning,
stacklevel=2,
)
if self._body_state_w.timestamp < self._sim_timestamp:
wp.launch(
shared_kernels.concat_body_pose_and_vel_to_state,
dim=(self.num_instances, self.num_bodies),
inputs=[
self.body_link_pose_w.warp,
self.body_com_vel_w.warp,
],
outputs=[
self._body_state_w.data,
],
device=self.device,
)
self._body_state_w.timestamp = self._sim_timestamp
return self._body_state_w_ta
@property
def body_link_state_w(self) -> ProxyArray:
"""Deprecated, same as :attr:`body_link_pose_w` and :attr:`body_link_vel_w`."""
warnings.warn(
"The `body_link_state_w` property will be deprecated in IsaacLab 4.0. Please use `body_link_pose_w` and "
"`body_link_vel_w` instead.",
DeprecationWarning,
stacklevel=2,
)
if self._body_link_state_w.timestamp < self._sim_timestamp:
wp.launch(
shared_kernels.concat_body_pose_and_vel_to_state,
dim=(self.num_instances, self.num_bodies),
inputs=[
self.body_link_pose_w.warp,
self.body_link_vel_w.warp,
],
outputs=[
self._body_link_state_w.data,
],
device=self.device,
)
self._body_link_state_w.timestamp = self._sim_timestamp
return self._body_link_state_w_ta
@property
def body_com_state_w(self) -> ProxyArray:
"""Deprecated, same as :attr:`body_com_pose_w` and :attr:`body_com_vel_w`."""
warnings.warn(
"The `body_com_state_w` property will be deprecated in IsaacLab 4.0. Please use `body_com_pose_w` and "
"`body_com_vel_w` instead.",
DeprecationWarning,
stacklevel=2,
)
if self._body_com_state_w.timestamp < self._sim_timestamp:
wp.launch(
shared_kernels.concat_body_pose_and_vel_to_state,
dim=(self.num_instances, self.num_bodies),
inputs=[
self.body_com_pose_w.warp,
self.body_com_vel_w.warp,
],
outputs=[
self._body_com_state_w.data,
],
device=self.device,
)
self._body_com_state_w.timestamp = self._sim_timestamp
return self._body_com_state_w_ta
