Hi, Before the weekend, we sat down with Bohdan and created the following idea for mouse picking subsystem: https://github.com/updraft/updraft/wiki/Mouse-Picking-Interface Basically, we propose to create a MapObject class that will represent a pickable object in the map. The mouse-click GUI handler will then pick all the intersected nodes and for each node (taking the foremost nodes first) find the nearest parent, that has a MapObject associated with it, in the OSG hierarchy. All plugins will then be notified by calling their HandleEvent function with the corresponding MapObject and other data as arguments - we don't think that there will ever be so many plugins or simultaneously picked MapObjects that this "notify everyone" approach could cause a significant slow-down. The only thing that we are unsure about are the context menus. Either we can have a single context menu and dynamically re-build it every time it is required or we can have a context menu for every object that will ever need to use one. In the current core interface, we are using the first approach and we chose it in our proposal as well. Cestmir & Bohdan To visit archive or unsubscribe, follow: //www.freelists.org/list/glideplan_swproj