TypeError in Path Planning Demo Due to Incorrect Pose Multiplication

[henryhcliu]

When running the path planning demo with SAPIEN 3.0.1 and mplib 0.2.1, the following error occurs:

TypeError: can't multiply sequence by non-int of type 'mplib.pymp.Pose'

The error originates from lines 616–618 in $PYTHON_SITE_PKG_PATH/mplib/planner.py, where a sequence is being multiplied by a Pose object, which is unsupported.

Proposed Fix:
Update the _transform_goal_to_wrt_base method to properly handle list/tuple inputs by converting them to a Pose before performing the transformation:

def _transform_goal_to_wrt_base(self, goal_pose: Pose) -> Pose:
    """Converts goal pose from T_world_goal to T_base_goal"""
    if isinstance(goal_pose, (list, tuple)):
        goal_pose = Pose(goal_pose[:3], goal_pose[3:])
    return self.robot.get_base_pose().inv() * goal_pose

With this change, the demo runs without errors.