How to read surface tags stored in graph (0.13.0-pre14)

Developers
1

Hi,
we use Graphhopper with the RacingBikeFlagEncoder and MountainBikeFlagEncoder for different routing profiles. Furthermore we added a DataFlagEncoder to retrieve the surface from the EdgeIteratorState.
Is it correct that with the newly released version 0.13.0-pre14 we can remove the DataFlagEncoder and read the surface directly from the graph? If so could you help me out where to start?

2

Yes, this was introduced and explained in the following pull request:

You only need to include the following in the configuration

graph.encoded_values: surface

Additionally I recommend to add: road_class,road_class_link,road_environment,max_speed,road_access

3

Thanks for the quick reply! I added the encoded_values to my configuration and regenerated the graph, but I always get “other” as surface. Is this code correct?

Graphhopper initialization:

ElevationProvider elevationProvider = new MultiSourceElevationProvider();
elevationProvider.setCalcMean(true);

EncodingManager encodingManager = EncodingManager.create(new RacingBikeFlagEncoder(), new MountainBikeFlagEncoder());

GraphHopper routingHopper = new GraphHopperOSM()
        .setDataReaderFile(filename)
        .init(new CmdArgs()
                .put("graph.elevation.smoothing", "true")
                .put("graph.encoded_values", "surface,road_class,road_class_link,road_environment,max_speed,road_access")
        )
        .setEncodingManager(encodingManager)
        .setMinNetworkSize(200, 200)
        .setGraphHopperLocation(routingPath)
        .setElevationProvider(elevationProvider);

CustomEdgeFilter:

public boolean accept(EdgeIteratorState edgeState) {
    Surface surface = edgeState.get(new EnumEncodedValue<Surface>(Surface.KEY, Surface.class));
    System.out.println(surface);
4

@karussell Is there any documentation or code examples for this new functionality? I can’t find any instructions in the pull request.

5

Currently there is no documentation for the Java usage, other than the tests.

You need to get the EnumEncodedValue from the EncodingManager:

surfaceEnc = encodingManager.getEnumEncodedValue(Surface.KEY, Surface.class)

Do this only once and use the surfaceEnc variable to access the edge properties multiple times via

surface = edge.get(surfaceEnc)

Does this help?

6

@karussell Thanks, I tried it out. However when I call hopper.getEncodingManager().getEnumEncodedValue(Surface.KEY, Surface.class); I get an IllegalArgumentException: Cannot find EncodedValue surface in collection: null.
While debugging I found out the encoded_values I specified in init are not available. Do I have to add another encoder or something else? I attached a screenshot of the encoded values in the method getEncodedValue in EncodingManager.

grafik
grafik.png1474Ă—366 52.4 KB

7

I did some more debugging and I think setEncodingManager(encodingManager) in my setup overwrites the encoding manager with the encoded values created by the init call.
How can I use my two encoding managers for racing bike and mountainbike without interfering with the encoded values?

EDIT: Found a solution, it’s working now. Code if anyone is interested:
GraphHopper routingHopper = new GraphHopperOSM()
.setDataReaderFile(filename)
.init(new CmdArgs()
.put(“graph.elevation.smoothing”, “true”)
.put(“graph.encoded_values”, “surface,road_class,road_class_link,road_environment,road_access”)
.put(“graph.flag_encoders”, “mtb,racingbike”)
)
.setMinNetworkSize(200, 200)
.setGraphHopperLocation(routingPath)
.setElevationProvider(elevationProvider);

8

Can you remove the init call and do:

new EncodingManager.Builder(4).add(someFlagEncoder).add(someTagParser).build();

1 Like
9

Thanks a lot for your help, it’s all working fine now!

1 Like