About the movement of objects in the simulation environment

[hahahalove57]

Hello, thank you for your excellent contribution！ I noticed that def clear_objects(self, object_names) in robosuite can modify the position or state of the relevant object without using env.step to control the robot colliding with object to change its position state. Is there any related function to directly control the object state in the simulation without the robot? If not, how to write the related function? That is, modify the relevant data in the sim

[kevin-thankyou-lin]

For sure!

What part of clear_objects doesn't work?

    def clear_objects(self, object_names):
        """
        Clears objects with the name @object_names out of the task space. This is useful
        for supporting task modes with single types of objects, as in
        @self.single_object_mode without changing the model definition.
        Args:
            object_names (str or list of str): Name of object(s) to remove from the task workspace
        """
        object_names = {object_names} if type(object_names) is str else set(object_names)
        for obj in self.model.mujoco_objects:
            if obj.name in object_names:
                self.sim.data.set_joint_qpos(obj.joints[0], np.array((10, 10, 10, 1, 0, 0, 0)))

the key line is self.sim.data.set_joint_qpos(obj.joints[0], np.array((10, 10, 10, 1, 0, 0, 0)))

[kevin-thankyou-lin]

You can try using this function:

def set_body_pose(
    data: mujoco.MjData,
    model: mujoco.MjModel,
    body_name: str,
    pos_xyz: np.ndarray,
    quat_wxyz: np.ndarray,
) -> None:
    """
    Set the position of a specified body in the model.

    Args:
        data (MjData): The MuJoCo data object.
        model (MjModel): The MuJoCo model object.
        body_name (str): Name of the body to set position for.
        position (np.ndarray): Target [x, y, z] position.
    """
    body_id = mujoco.mj_name2id(model, mujoco.mjtObj.mjOBJ_BODY, body_name)
    # Retrieve the joint type
    joint_id = model.body_jntadr[body_id]
    if joint_id >= 0 and model.jnt_type[joint_id] == 0:  # type 0 indicates a free joint
        # Set qpos for free joint: [pos_x, pos_y, pos_z, quat_w, quat_x, quat_y, quat_z]
        qpos_start = model.jnt_qposadr[joint_id]
        data.qpos[qpos_start : qpos_start + 3] = pos_xyz
        data.qpos[qpos_start + 3 : qpos_start + 7] = quat_wxyz
    else:
        raise ValueError(
            f"Body '{body_name}' does not have a free joint or is missing a joint."
        )

For example:

            set_body_pose(
                env.sim.data._data,
                env.sim.model._model,
                "object_name",
                np.zeros(3),
                np.array([1, 0, 0, 0]),
            )