Accessing data of different layers in Costmap2DROS

edit

I would like to access the data of the internal master_grid of the obstacle_layer. I am working in another layer and right now I am reading the values out of the layered_costmap_, which works fine like that:

  costmap_2d::Costmap2D* costmap = layered_costmap_->getCostmap();

Also, if I would be within the obstacle_layer, I would access the data of its own master_grid like that:

  unsigned char* master_array = master_grid.getCharMap();

But how would I access the master_grid of the obstacle_layer from another layer? Thanks!

UPDATE:

I think I found a working piece of code which answers like 95 % of my question. So the code searches through all the layers of the COSTMAP (actually it is a layered costmap of type costmap_2d::Costmap2DROS) and operates on the one which matches a predefined string (layer_sear_string_). But can somebody help me how to find the name of the layered costmap global_planner when running move_base?

std::vector<boost::shared_ptr<costmap_2d::Layer> >* plugins = COSTMAP->getLayeredCostmap()->getPlugins();

for (std::vector<boost::shared_ptr<costmap_2d::Layer> >::iterator pluginp = plugins->begin(); pluginp != plugins->end(); ++pluginp) {

    boost::shared_ptr<costmap_2d::Layer> plugin = *pluginp;

    if(plugin->getName().find(layer_search_string_)!=std::string::npos) {
        boost::shared_ptr<costmap_2d::ObstacleLayer> costmap;
        costmap = boost::static_pointer_cast<costmap_2d::ObstacleLayer>(plugin);
        unsigned char* grid = costmap->getCharMap();

        // do sth with it

    }
}

Code found here.