THOR might be a good alternative, but the A* algorithm OsmAnd uses is just fine. I agree that OSRM is too limited due to its inflexibility.
It is the implementation of the A* algorithm in OsmAnd that is wrong (from my point of view). OsmAnd is literally the only app that uses a heuristic coefficient of 1.0 thereby increasing both memory usage and calculation time extremely. And it sometimes even calculates the wrong route (due to over-optimization?). I use a heuristic coefficient of 1.25 or 1.3 which makes the calculation 3-4x as fast!! and I can calculate routes up to 2000 km (less memory usage) where I could calculate up to 800 km (1.5GB memory in my phone) . And routes were never worse and in some cases even better: faster and shorter! With that configured the route calculation is still not the fastest but completely acceptable. There is only one disadvantage: deviating from the default 1.0 in OsmAnd makes that blocked roads (by users themselves for whatever reason) are no longer recognised. I assume that is an omission in OsmAnd. I can't consider it a bug as Victor developed OsmAnd for that hc=1.0 (but I still I think it is a bug :) as other A* algorithms apps have no problem with that). Next to that: OsmAnd knows speed penalties for traffic lights, speed bumps and the like. It seems that THOR supports that too (dynamic run-time costing) but is not yet implemented, but maybe I'm wrong. The other reason for me for not using OsmAnd for car navigation is the slow rendering of the screen. 2016-10-02 12:11 GMT+02:00 'Norbert' via Osmand <[email protected]>: > OsmAnd needs a new routing engine because of bad performance. Graphhopper > and OSRM do not fulfill the requirements because they don't support > conditional edge-weights at query-time*. THis is necessary to support > options like avoid highways and so on without the need for a separate > CH-graph for each combination of options. > > Competitor maps.me suffers from a similar problem**. The use fast OSRM > engine but can't offer routing options (avoid highways etc.). > > It should be investigated if THOR*** engine (Tiled Hierarchical Open > Routing) which supports* multi-modal routing *can be implemented in > OsmAnd to replace the current routing engine. > > > > * https://github.com/Project-OSRM/osrm-backend/issues/2377 > ** https://github.com/mapsme/omim/issues/1888 > *** https://github.com/valhalla/thor > *** https://mapzen.com/blog/valhalla-intro/ > > -- > You received this message because you are subscribed to the Google Groups > "Osmand" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Osmand" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
