[Question] Python: How do you get the directly following Lanelet?

[ligonap]

Hello! I have two questions about the Python implementation of Lanelet2.

1) How can the immediately following lanelet be determined based on a lanelet? The neighbouring lanelets can be determined using leftBoundand rightBound, whereby the original lanelet is also returned. E.g.: lmap.laneletLayer.findUsages(lanelet.rightBound) A lanelet.frontBound is somehow missing.

2) How can I determine or return the linestrings or points of a lanelet? So that I get the start points of following lineStrings via the lineStrings and the end points and thereby the following lanelet.

[ligonap]

To find the following lanelet I tested the following from tutorial.py:

        projector = lanelet2.projection.UtmProjector(lanelet2.io.Origin(49, 8.4))
        map = lanelet2.io.load('mapping_example.osm', projector)

        traffic_rules = lanelet2.traffic_rules.create(lanelet2.traffic_rules.Locations.Germany,
                                                  lanelet2.traffic_rules.Participants.Vehicle)

        graph = lanelet2.routing.RoutingGraph(map, traffic_rules)
        lanelet = map.laneletLayer[4984315]
        print(graph.following(lanelet))

There is one element in the output. So far so good.

If I test this with my map (Origin(0, 0)), where actually no TrafficRules are intended (I used the same TrafficRules), because this is a kind of highway, I get no element. But in my map there are 591 lanelets. The highway has three lanes of 197 lanelets each. Somehow the routine cannot be reproduced with other cards.

[poggenhans]

Well, looks like your map is incorrect then. Make sure the lanelets are properly tagged as road lanelets (see here), otherwise they won't become part of the vehicle routing graph.

[ligonap]

My lanelets are defined as follows:

<tag k="location" v="urban" />
<tag k="one_way" v="yes" />
<tag k="participant" v="vehicle:robot" />
<tag k="region" v="de" />
<tag k="subtype" v="raceway" />
<tag k="type" v="lanelet" />

Is it the vehicle:robot?

To find the following lanelet, I helped myself with a dictionary { lanelet_id : (left_line_id, right_line_id) }.

[poggenhans]

Is it the vehicle:robot?

Yes. This means: This road is only for robots. subtype=raceway is also an undefined value, so it's assumed to be a non-drivable lanelet.

[ligonap]

I have changed the entries as follows:

<tag k="location" v="nonurban" />
<tag k="one_way" v="yes" />
<tag k="region" v="de" />
<tag k="subtype" v="highway" />
<tag k="type" v="lanelet" />

And the following code successfully gives me the ID of the following lanelet.

traffic_rules = lanelet2.traffic_rules.create(lanelet2.traffic_rules.Locations.Germany, lanelet2.traffic_rules.Participants.Vehicle)
graph = lanelet2.routing.RoutingGraph(self.lmap, traffic_rules)
following_Lanelet_id = (graph.following(lanelet))[0].id

Thank you for the tips.

[github-actions[bot]]

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[github-actions[bot]]

This issue was closed because it has been stalled for 30 days with no activity.