Adds support for drift in `RayCaster` and makes fields in `ContactSensorData` optional (#201)

# Description

This MR adds support for 2D drift into the `RayCaster`. It also makes
certain attributes in the `ContactSensorData` optional since they are
not needed by default.

## Type of change

- Bug fix (non-breaking change which fixes an issue)
- New feature (non-breaking change which adds functionality)
- Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- This change requires a documentation update

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./orbit.sh --format`
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [x] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file

source/extensions/omni.isaac.orbit/config/extension.toml

 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.9.13"
+version = "0.9.14"
 
 # Description
 title = "ORBIT framework for Robot Learning"

source/extensions/omni.isaac.orbit/docs/CHANGELOG.rst

 Changelog
 ---------
 
+0.9.14 (2023-10-21)
+~~~~~~~~~~~~~~~~~~~
+
+Added
+^^^^^
+
+* Added 2-D drift (i.e. along x and y) to the :class:`omni.isaac.orbit.sensors.RayCaster` class.
+* Added flags to the :class:`omni.isaac.orbit.sensors.ContactSensorCfg` to optionally obtain the
+  sensor origin and air time information. Since these are not required by default, they are
+  disabled by default.
+
+Fixed
+^^^^^
+
+* Fixed the handling of contact sensor history buffer in the :class:`omni.isaac.orbit.sensors.ContactSensor` class.
+  Earlier, the buffer was not being updated correctly.
+
+
 0.9.13 (2023-10-20)
 ~~~~~~~~~~~~~~~~~~~
 

source/extensions/omni.isaac.orbit/omni/isaac/orbit/sensors/contact_sensor/contact_sensor.py

@@ -3,6 +3,8 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
+# Ignore optional memory usage warning globally
+# pyright: reportOptionalSubscript=false
 
 from __future__ import annotations
 
@@ -137,11 +139,17 @@ class ContactSensor(SensorBase):
         if env_ids is None:
             env_ids = slice(None)
         # reset accumulative data buffers
-        self._data.current_air_time[env_ids] = 0.0
-        self._data.last_air_time[env_ids] = 0.0
         self._data.net_forces_w[env_ids] = 0.0
-        # reset the data history
         self._data.net_forces_w_history[env_ids] = 0.0
+        if self.cfg.history_length > 0:
+            self._data.net_forces_w_history[env_ids] = 0.0
+        # reset force matrix
+        if len(self.cfg.filter_prim_paths_expr) != 0:
+            self._data.force_matrix_w[env_ids] = 0.0
+        # reset the current air time
+        if self.cfg.track_air_time:
+            self._data.current_air_time[env_ids] = 0.0
+            self._data.last_air_time[env_ids] = 0.0
         # Set all reset sensors to not outdated since their value won't be updated till next sim step.
         self._is_outdated[env_ids] = False
 
@@ -202,15 +210,24 @@ class ContactSensor(SensorBase):
                 f"\n\tResolved prim paths: {body_names_regex}"
             )
 
-        # fill the data buffer
+        # prepare data buffers
+        self._data.net_forces_w = torch.zeros(self._num_envs, self._num_bodies, 3, device=self._device)
+        # optional buffers
+        # -- history of net forces
+        if self.cfg.history_length > 0:
+            self._data.net_forces_w_history = torch.zeros(
+                self._num_envs, self.cfg.history_length, self._num_bodies, 3, device=self._device
+            )
+        else:
+            self._data.net_forces_w_history = self._data.net_forces_w.unsqueeze(1)
+        # -- pose of sensor origins
+        if self.cfg.track_pose:
             self._data.pos_w = torch.zeros(self._num_envs, self._num_bodies, 3, device=self._device)
             self._data.quat_w = torch.zeros(self._num_envs, self._num_bodies, 4, device=self._device)
+        # -- air time between contacts
+        if self.cfg.track_air_time:
             self._data.last_air_time = torch.zeros(self._num_envs, self._num_bodies, device=self._device)
             self._data.current_air_time = torch.zeros(self._num_envs, self._num_bodies, device=self._device)
-        self._data.net_forces_w = torch.zeros(self._num_envs, self._num_bodies, 3, device=self._device)
-        self._data.net_forces_w_history = torch.zeros(
-            self._num_envs, self.cfg.history_length + 1, self._num_bodies, 3, device=self._device
-        )
         # force matrix: (num_sensors, num_bodies, num_shapes, num_filter_shapes, 3)
         if len(self.cfg.filter_prim_paths_expr) != 0:
             num_shapes = self.contact_physx_view.sensor_count // self._num_bodies
@@ -224,17 +241,16 @@ class ContactSensor(SensorBase):
         # default to all sensors
         if len(env_ids) == self._num_envs:
             env_ids = slice(None)
-        # obtain the poses of the sensors:
-        # TODO decide if we really to track poses -- This is the body's CoM. Not contact location.
-        pose = self.body_physx_view.get_transforms()
-        self._data.pos_w[env_ids] = pose.view(-1, self._num_bodies, 7)[env_ids, :, :3]
-        self._data.quat_w[env_ids] = pose.view(-1, self._num_bodies, 7)[env_ids, :, 3:]
 
         # obtain the contact forces
         # TODO: We are handling the indexing ourself because of the shape; (N, B) vs expected (N * B).
         #   This isn't the most efficient way to do this, but it's the easiest to implement.
         net_forces_w = self.contact_physx_view.get_net_contact_forces(dt=self._sim_physics_dt)
         self._data.net_forces_w[env_ids, :, :] = net_forces_w.view(-1, self._num_bodies, 3)[env_ids]
+        # update contact force history
+        if self.cfg.history_length > 0:
+            self._data.net_forces_w_history[env_ids, 1:] = self._data.net_forces_w_history[env_ids, :-1].clone()
+            self._data.net_forces_w_history[env_ids, 0] = self._data.net_forces_w[env_ids]
 
         # obtain the contact force matrix
         if len(self.cfg.filter_prim_paths_expr) != 0:
@@ -245,14 +261,13 @@ class ContactSensor(SensorBase):
             force_matrix_w = self.contact_physx_view.get_contact_force_matrix(dt=self._sim_physics_dt)
             force_matrix_w = force_matrix_w.view(-1, self._num_bodies, num_shapes, num_filters, 3)
             self._data.force_matrix_w[env_ids] = force_matrix_w[env_ids]
-
-        # update contact force history
-        previous_net_forces_w = self._data.net_forces_w_history.clone()
-        self._data.net_forces_w_history[env_ids, 0, :, :] = self._data.net_forces_w[env_ids, :, :]
-        if self.cfg.history_length > 0:
-            self._data.net_forces_w_history[env_ids, 1:, :, :] = previous_net_forces_w[env_ids, :-1, :, :]
-
-        # contact state
+        # obtain the pose of the sensor origin
+        if self.cfg.track_pose:
+            pose = self.body_physx_view.get_transforms()
+            self._data.pos_w[env_ids] = pose.view(-1, self._num_bodies, 7)[env_ids, :, :3]
+            self._data.quat_w[env_ids] = pose.view(-1, self._num_bodies, 7)[env_ids, :, 3:]
+        # obtain the air time
+        if self.cfg.track_air_time:
             # -- time elapsed since last update
             # since this function is called every frame, we can use the difference to get the elapsed time
             elapsed_time = self._timestamp[env_ids] - self._timestamp_last_update[env_ids]
@@ -276,4 +291,10 @@ class ContactSensor(SensorBase):
         net_contact_force_w = torch.norm(self._data.net_forces_w, dim=-1)
         marker_indices = torch.where(net_contact_force_w > 1.0, 0, 1)
         # check if prim is visualized
-        self.contact_visualizer.visualize(self._data.pos_w.view(-1, 3), marker_indices=marker_indices.view(-1))
+        if self.cfg.track_pose:
+            frame_origins: torch.Tensor = self._data.pos_w
+        else:
+            pose = self.body_physx_view.get_transforms()
+            frame_origins = pose.view(-1, self._num_bodies, 7)[:, :, :3]
+        # visualize
+        self.contact_visualizer.visualize(frame_origins.view(-1, 3), marker_indices=marker_indices.view(-1))

source/extensions/omni.isaac.orbit/omni/isaac/orbit/sensors/contact_sensor/contact_sensor_cfg.py

@@ -18,6 +18,12 @@ class ContactSensorCfg(SensorBaseCfg):
 
     class_type: type = ContactSensor
 
+    track_pose: bool = False
+    """Whether to track the pose of the sensor's origin. Defaults to False."""
+
+    track_air_time: bool = False
+    """Whether to track the air time of the bodies (time between contacts). Defaults to False."""
+
     filter_prim_paths_expr: list[str] = list()
     """The list of primitive paths to filter contacts with.
 

source/extensions/omni.isaac.orbit/omni/isaac/orbit/sensors/contact_sensor/contact_sensor_data.py

@@ -13,15 +13,22 @@ from dataclasses import dataclass
 class ContactSensorData:
     """Data container for the contact reporting sensor."""
 
-    pos_w: torch.Tensor = None
+    pos_w: torch.Tensor | None = None
     """Position of the sensor origin in world frame.
 
     Shape is (N, 3), where ``N`` is the number of sensors.
+
+    Note:
+        If the :attr:`ContactSensorCfg.track_pose` is False, then this qunatity is None.
     """
-    quat_w: torch.Tensor = None
+
+    quat_w: torch.Tensor | None = None
     """Orientation of the sensor origin in quaternion ``(w, x, y, z)`` in world frame.
 
     Shape is (N, 4), where ``N`` is the number of sensors.
+
+    Note:
+        If the :attr:`ContactSensorCfg.track_pose` is False, then this qunatity is None.
     """
 
     net_forces_w: torch.Tensor = None
@@ -29,6 +36,7 @@ class ContactSensorData:
 
     Shape is (N, B, 3), where ``N`` is the number of sensors and ``B`` is the number of bodies in each sensor.
     """
+
     net_forces_w_history: torch.Tensor = None
     """The net contact forces in world frame.
 
@@ -38,22 +46,30 @@ class ContactSensorData:
     In the history dimension, the first index is the most recent and the last index is the oldest.
     """
 
-    force_matrix_w: torch.Tensor = None
+    force_matrix_w: torch.Tensor | None = None
     """The contact forces filtered between the sensor bodies and filtered bodies in world frame.
 
     Shape is (N, B, S, M, 3), where ``N`` is the number of sensors, ``B`` is number of bodies in each sensor,
     ``S`` is number of shapes per body and ``M`` is the number of filtered bodies.
 
-    If the :attr:`ContactSensorCfg.filter_prim_paths_expr` is empty, then this tensor will be empty.
+    Note:
+        If the :attr:`ContactSensorCfg.filter_prim_paths_expr` is empty, then this quantity is None.
     """
 
-    last_air_time: torch.Tensor = None
+    last_air_time: torch.Tensor | None = None
     """Time spent (in s) in the air before the last contact.
 
     Shape is (N,), where ``N`` is the number of sensors.
+
+    Note:
+        If the :attr:`ContactSensorCfg.track_air_time` is False, then this quantity is None.
     """
-    current_air_time: torch.Tensor = None
+
+    current_air_time: torch.Tensor | None = None
     """Time spent (in s) in the air since the last contact.
 
     Shape is (N,), where ``N`` is the number of sensors.
+
+    Note:
+        If the :attr:`ContactSensorCfg.track_air_time` is False, then this quantity is None.
     """

source/extensions/omni.isaac.orbit/omni/isaac/orbit/sensors/ray_caster/ray_caster.py

@@ -95,6 +95,15 @@ class RayCaster(SensorBase):
         if self.ray_visualizer is not None:
             self.ray_visualizer.set_visibility(debug_vis)
 
+    def reset(self, env_ids: Sequence[int] | None = None):
+        # reset the timers and counters
+        super().reset(env_ids)
+        # resolve None
+        if env_ids is None:
+            env_ids = slice(None)
+        # resample the drift
+        self.drift[env_ids].uniform_(*self.cfg.drift_range)
+
     """
     Implementation.
     """
@@ -180,7 +189,8 @@ class RayCaster(SensorBase):
         # repeat the rays for each sensor
         self.ray_starts = self.ray_starts.repeat(self._view.count, 1, 1)
         self.ray_directions = self.ray_directions.repeat(self._view.count, 1, 1)
-
+        # prepare drift
+        self.drift = torch.zeros(self._view.count, 3, device=self.device)
         # fill the data buffer
         self._data.pos_w = torch.zeros(self._view.count, 3, device=self._device)
         self._data.quat_w = torch.zeros(self._view.count, 4, device=self._device)
@@ -190,6 +200,7 @@ class RayCaster(SensorBase):
         """Fills the buffers of the sensor data."""
         # obtain the poses of the sensors
         pos_w, quat_w = self._view.get_world_poses(env_ids, clone=False)
+        pos_w += self.drift[env_ids]
         self._data.pos_w[env_ids] = pos_w
         self._data.quat_w[env_ids] = quat_w
 

source/extensions/omni.isaac.orbit/omni/isaac/orbit/sensors/ray_caster/ray_caster_cfg.py

@@ -53,3 +53,9 @@ class RayCasterCfg(SensorBaseCfg):
 
     max_distance: float = 100.0
     """Maximum distance (in meters) from the sensor to ray cast to. Defaults to 100.0."""
+
+    drift_range: tuple[float, float] = (0.0, 0.0)
+    """The range of drift (in meters) to add to the ray starting positions (xyz). Defaults to (0.0, 0.0).
+
+    For floating base robots, this is useful for simulating drift in the robot's pose estimation.
+    """

source/extensions/omni.isaac.orbit/test/isaacsim/test_torch.py

@@ -33,6 +33,28 @@ class TestTorchOperations(unittest.TestCase):
         self.assertEqual(my_tensor[slice(None), 0, 0].shape, (400,))
         self.assertEqual(my_tensor[:, 0, 0].shape, (400,))
 
+    def test_array_copying(self):
+        """Check how indexing effects the returned tensor."""
+
+        size = (400, 300, 5)
+        my_tensor = torch.rand(size, device="cuda:0")
+
+        # obtain a slice of the tensor
+        my_slice = my_tensor[0, ...]
+        self.assertEqual(my_slice.untyped_storage().data_ptr(), my_tensor.untyped_storage().data_ptr())
+
+        # obtain a slice over ranges
+        my_slice = my_tensor[0:2, ...]
+        self.assertEqual(my_slice.untyped_storage().data_ptr(), my_tensor.untyped_storage().data_ptr())
+
+        # obtain a slice over list
+        my_slice = my_tensor[[0, 1], ...]
+        self.assertNotEqual(my_slice.untyped_storage().data_ptr(), my_tensor.untyped_storage().data_ptr())
+
+        # obtain a slice over tensor
+        my_slice = my_tensor[torch.tensor([0, 1]), ...]
+        self.assertNotEqual(my_slice.untyped_storage().data_ptr(), my_tensor.untyped_storage().data_ptr())
+
 
 if __name__ == "__main__":
     unittest.main()