Re: [ompl-users] Removing vertices from PRM graph

[Mark M. <mm...@ri...>]

Hadar,

What you want sounds very similar to using LazyPRM initialized with saved PlannerData. The idea is that you generate a roadmap/graph with any planner, extract the PlannerData (optional save and load to/from disk), and construct a LazyPRM instance with the PlannerData as argument.

The mutex is used exactly so you *can* use multiple threads safely. You need to be careful to remove each vertex/edge only once and make sure that no vertex/edge is accessed by other threads as it is being removed.

Best,

Mark



> On Jan 6, 2021, at 9:55 AM, hadar sinvani <had...@gm...> wrote:
> 
> Hi Mark,
> 
> Thank you for your quick reply.
> 
> As you suggested, I will look through the boost graph library API for the relevant functions and write this method by myself.
> 
> I intend to iterate through the vertices data structure and to check again every vertex with IsValid   (Is Valid will be different, of course, from the IsValid I used during roadmap construction).
> 
> According to the returned value, the method will keep/remove the examined vertex and its edges.
> 
> I would appreciate your advice regarding the function I intend to write.
> 
> In PRM implementation, I saw you use mutex every time you add a milestone or an edge.  Does this mean that my function cannot run multiple threads so that each thread will iterate through different part of the vertices data structure?
> 
> Best and a happy new year,
> 
> Hadar
> 
> 
> 
> 
> 
> On Wed, Jan 6, 2021, 01:16 Mark Moll <mm...@ri... <mailto:mm...@ri...>> wrote:
> Hi Hadar,
> 
> There is no method for this at the moment. You need to write your own method that will call Boost.Graph functions to remove specific vertices and any incident edges.
> 
> Best,
> 
> Mark
> 
> 
> 
>> On Jan 5, 2021, at 7:25 AM, hadar sinvani <had...@gm... <mailto:had...@gm...>> wrote:
>> 
>> Hello,
>> 
>> I'm using the geometric prm planner.
>> 
>> At first, the constructRoadmap function is being called once, following several calls to solve and clearQuery functions. 
>> 
>> I would also like to update my graph between calls and to remove specific vertices, therefore the clear function that clears ALL internal data structure is not a good option for me…
>> 
>> Is there a function that iterates through the vertices data structure and removes specific vertices from the graph?
>> 
>> Best,
>> 
>> Hadar
>> 
>> _______________________________________________
>> ompl-users mailing list
>> omp...@li... <mailto:omp...@li...>
>> https://lists.sourceforge.net/lists/listinfo/ompl-users <https://lists.sourceforge.net/lists/listinfo/ompl-users>
>