Added ability to change start pose of stretch

[hello-robot-shehab]

Added the ability to specify the start translation and rotation.

To test, run this start_pose.py example script (https://github.com/hello-robot/stretch_mujoco/pull/98/changes#diff-c99c383503c8304ed2a4a454ff0f836b58ef84a2f05401ddd43bf6ffc7f6c5ae):

from stretch_mujoco.stretch_mujoco_simulator import StretchMujocoSimulator
from scipy.spatial.transform import Rotation as R

if __name__ == "__main__":

    translation_m = [0.1, -0.2, 0]

    # Convert euler angles to quaternion
    euler_angles_degrees = [0, 0, -90] # Example: roll, pitch, yaw (x, y, z)
    rotation_obj = R.from_euler('xyz', euler_angles_degrees, degrees=True)
    rotation_quat = rotation_obj.as_quat(scalar_first=True)


    sim = StretchMujocoSimulator(
        start_translation=translation_m,
        start_rotation_quat=rotation_quat
    )

    sim.start(headless=False)

    while sim.is_running(): ...

[hello-binit]

Hey @hello-robot-shehab, I'm seeing this error when running uv run examples/test_one_process.py. Are you seeing this too?

Traceback (most recent call last):
  File "/home/binitshah/repos/new_work_on_mujoco/stretch_mujoco/examples/test_one_process.py", line 16, in <module>
    MujocoServer.launch_server(
  File "/home/binitshah/repos/new_work_on_mujoco/stretch_mujoco/stretch_mujoco/mujoco_server.py", line 198, in launch_server
    server = cls(scene_xml_path, model, stop_mujoco_process_event, data_proxies,start_translation , start_rotation_quat)
  File "/home/binitshah/repos/new_work_on_mujoco/stretch_mujoco/stretch_mujoco/mujoco_server.py", line 233, in __init__
    model = self.change_start_pose(translation = start_translation,  rotation_quat=start_rotation_quat, xml_path=scene_xml_path)
  File "/home/binitshah/repos/new_work_on_mujoco/stretch_mujoco/stretch_mujoco/mujoco_server.py", line 211, in change_start_pose
    return MjModel.from_xml_string(spec.to_xml())
ValueError: Error: Error opening file 'assets/base_link_0.obj': No such file or directory

[hello-robot-shehab]

Hey @hello-robot-shehab, I'm seeing this error when running uv run examples/test_one_process.py. Are you seeing this too?

Traceback (most recent call last):
  File "/home/binitshah/repos/new_work_on_mujoco/stretch_mujoco/examples/test_one_process.py", line 16, in <module>
    MujocoServer.launch_server(
  File "/home/binitshah/repos/new_work_on_mujoco/stretch_mujoco/stretch_mujoco/mujoco_server.py", line 198, in launch_server
    server = cls(scene_xml_path, model, stop_mujoco_process_event, data_proxies,start_translation , start_rotation_quat)
  File "/home/binitshah/repos/new_work_on_mujoco/stretch_mujoco/stretch_mujoco/mujoco_server.py", line 233, in __init__
    model = self.change_start_pose(translation = start_translation,  rotation_quat=start_rotation_quat, xml_path=scene_xml_path)
  File "/home/binitshah/repos/new_work_on_mujoco/stretch_mujoco/stretch_mujoco/mujoco_server.py", line 211, in change_start_pose
    return MjModel.from_xml_string(spec.to_xml())
ValueError: Error: Error opening file 'assets/base_link_0.obj': No such file or directory

Yes, pushing a fix now, thanks!

[hello-robot-shehab]

Fixed! Thanks for catching that @hello-binit! I also fixed the quaternion real-part [1,0,0,0] that we talked about before. Thanks!