Hi all,

we are having difficulty reading the data stored by moveit regarding the persistent PRM planner.

Here is a description of our problem. In moveit, we added The PRM persistent to benefit from mutli-query planners by adding it in ompl_planning.yaml:

multi_query_planning_enabled: true
store_planner_data: true
load_planner_data: true planner_data_path: /path/to/roadmap.graph

We would like to read the file generated by moveit using the ompl functions in order to determine the information regarding the previously generated graph. The problem is that we got a "Failed to load PlannerData: StateSpace signature mismatch" . This error probably due to the initial space definition. Here is our python code as an example:

from ompl import base
from ompl import base as ob

space = ob.SE3StateSpace
si = ob.SpaceInformation(space)
data = ob.PlannerData(si);
dataStorage = ob.PlannerDataStorage()
path = "data_one.graph"
dataStorage.load(path,data)
print(data.numVertices())
print(data.numGoalVertices())

We managed to determine the signature of the file generated by Moveit which corresponds to 2 0 6. 0 here corresponds to STATESPACEUNKNOWN (default one).

How could we read this file and what state space does Moveit use?

Best regards.

We are using Noetic, Ubuntu 20.04 LTS and the versions associated to that release.