Separates joint state setters inside Articulation class (#1751)

# Description

Previously in the Articulation class, there was a single method for
setting joint state. However, it is desirable at times to only set joint
position or velocity. For instance, for randomization events that pushes
a joint by adding a random velocity to it.

This MR separates the `write_joint_state_to_sim` into separate setters
for joint positions and joint velocities. This goes inline with the
method to set root pose, root velocity or the root state.

## Type of change

- New feature (non-breaking change which adds functionality)

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [x] 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
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

---------

Signed-off-by: Mayank Mittal <[email protected]>
Co-authored-by: Kelly Guo <[email protected]>

Author: Mayankm96

source/isaaclab/config/extension.toml

@@ -1,7 +1,7 @@
 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.34.6"
+version = "0.34.7"
 
 # Description
 title = "Isaac Lab framework for Robot Learning"

source/isaaclab/docs/CHANGELOG.rst

@@ -1,6 +1,18 @@
 Changelog
 ---------
 
+0.34.7 (2025-03-04)
+~~~~~~~~~~~~~~~~~~~
+
+Added
+^^^^^
+
+* Added methods inside the :class:`omni.isaac.lab.assets.Articulation` class to set the joint
+  position and velocity for the articulation. Previously, the joint position and velocity could
+  only be set using the :meth:`omni.isaac.lab.assets.Articulation.write_joint_state_to_sim` method,
+  which didn't allow setting the joint position and velocity separately.
+
+
 0.34.6 (2025-03-02)
 ~~~~~~~~~~~~~~~~~~~
 

source/isaaclab/isaaclab/assets/articulation/articulation.py

@@ -484,6 +484,23 @@ def write_joint_state_to_sim(
             joint_ids: The joint indices to set the targets for. Defaults to None (all joints).
             env_ids: The environment indices to set the targets for. Defaults to None (all environments).
         """
+        # set into simulation
+        self.write_joint_position_to_sim(position, joint_ids=joint_ids, env_ids=env_ids)
+        self.write_joint_velocity_to_sim(velocity, joint_ids=joint_ids, env_ids=env_ids)
+
+    def write_joint_position_to_sim(
+        self,
+        position: torch.Tensor,
+        joint_ids: Sequence[int] | slice | None = None,
+        env_ids: Sequence[int] | slice | None = None,
+    ):
+        """Write joint positions to the simulation.
+
+        Args:
+            position: Joint positions. Shape is (len(env_ids), len(joint_ids)).
+            joint_ids: The joint indices to set the targets for. Defaults to None (all joints).
+            env_ids: The environment indices to set the targets for. Defaults to None (all environments).
+        """
         # resolve indices
         physx_env_ids = env_ids
         if env_ids is None:
@@ -496,15 +513,41 @@ def write_joint_state_to_sim(
             env_ids = env_ids[:, None]
         # set into internal buffers
         self._data.joint_pos[env_ids, joint_ids] = position
-        self._data.joint_vel[env_ids, joint_ids] = velocity
-        self._data._previous_joint_vel[env_ids, joint_ids] = velocity
-        self._data.joint_acc[env_ids, joint_ids] = 0.0
         # Need to invalidate the buffer to trigger the update with the new root pose.
         self._data._body_state_w.timestamp = -1.0
         self._data._body_link_state_w.timestamp = -1.0
         self._data._body_com_state_w.timestamp = -1.0
         # set into simulation
         self.root_physx_view.set_dof_positions(self._data.joint_pos, indices=physx_env_ids)
+
+    def write_joint_velocity_to_sim(
+        self,
+        velocity: torch.Tensor,
+        joint_ids: Sequence[int] | slice | None = None,
+        env_ids: Sequence[int] | slice | None = None,
+    ):
+        """Write joint velocities to the simulation.
+
+        Args:
+            velocity: Joint velocities. Shape is (len(env_ids), len(joint_ids)).
+            joint_ids: The joint indices to set the targets for. Defaults to None (all joints).
+            env_ids: The environment indices to set the targets for. Defaults to None (all environments).
+        """
+        # resolve indices
+        physx_env_ids = env_ids
+        if env_ids is None:
+            env_ids = slice(None)
+            physx_env_ids = self._ALL_INDICES
+        if joint_ids is None:
+            joint_ids = slice(None)
+        # broadcast env_ids if needed to allow double indexing
+        if env_ids != slice(None) and joint_ids != slice(None):
+            env_ids = env_ids[:, None]
+        # set into internal buffers
+        self._data.joint_vel[env_ids, joint_ids] = velocity
+        self._data._previous_joint_vel[env_ids, joint_ids] = velocity
+        self._data.joint_acc[env_ids, joint_ids] = 0.0
+        # set into simulation
         self.root_physx_view.set_dof_velocities(self._data.joint_vel, indices=physx_env_ids)
 
     def write_joint_stiffness_to_sim(