.. _concepts_sensors:
.. _overview_sensors:

Sensors
========

.. seealso::

   These pages are the source of truth for the ``isaaclab-using-sensors-actuators`` agent skill
   (`skills/user/use-sensors-actuators/ <../../../../skills/user/use-sensors-actuators/SKILL.md>`__).
   When sensor behavior changes, keep the API documentation, maintained demos, these concept pages,
   and the skill synchronized.

Sensors turn simulation state or rendered scene data into batched measurements. Every Isaac Lab
sensor derives from :class:`~isaaclab.sensors.SensorBase` and follows the same lifecycle:

* ``prim_path`` selects the prim or prims measured in every cloned environment.
* ``update_period`` sets the sampling period in simulated seconds. A value of ``0.0`` samples every
  simulation step.
* :meth:`~isaaclab.sensors.SensorBase.update` advances the sensor clock. Sensor data is evaluated
  lazily when the :attr:`~isaaclab.sensors.SensorBase.data` property is read, unless recomputation or
  debug visualization is requested.
* :meth:`~isaaclab.sensors.SensorBase.reset` clears per-environment timestamps and internal state.

Sensor data is exposed through :class:`~isaaclab.utils.warp.ProxyArray` buffers, including camera
outputs. Use the ``torch`` property for a cached zero-copy Torch view or ``warp`` for the underlying
Warp array.

Choose a sensor
---------------

.. list-table::
   :header-rows: 1
   :widths: 28 47 25

   * - Sensor
     - Measurement
     - Typical use
   * - :doc:`camera`
     - Renderer-produced color, depth, normals, motion, and segmentation images
     - Vision observations and synthetic data
   * - :doc:`ray_caster`
     - First collision locations for configurable ray patterns
     - Terrain sensing, lidar-style queries, and ray-cast cameras
   * - :doc:`contact_sensor`
     - Net and filtered contact forces, contact points, friction, and contact timing
     - Locomotion, grasping, and collision events
   * - :doc:`frame_transformer`
     - Relative and world poses for configured frames
     - End-effector, foot, and object tracking
   * - :doc:`imu`
     - Angular velocity and proper linear acceleration
     - Inertial observations
   * - :doc:`pva`
     - Ground-truth pose, velocity, coordinate acceleration, and projected gravity
     - State estimation and privileged observations
   * - :doc:`joint_wrench_sensor`
     - Incoming joint reaction force and torque
     - Force/torque sensing and contact-rich control

.. toctree::
   :maxdepth: 1
   :hidden:

   camera
   ray_caster
   contact_sensor
   frame_transformer
   imu
   pva
   joint_wrench_sensor