lanelet2 Graph

[ramdort]

Hello All,
I have a lanelet2 format of map1 of carla. I have converted it to graphfile .gv now each lanelet of the map is a node on the graph.
I want to find a way to know what does each node on a graph represent on the map. In other words, I need a function that takes the longitudinal and lateral coordinates and returns to me the corresponding node in the graph. does the API offer that, how can i make the graph keeps the geographical information to it ? any guiding for this task is appreciated

Regards,

[poggenhans]

How about findNearest? https://github.com/fzi-forschungszentrum-informatik/Lanelet2/blob/master/lanelet2_core/include/lanelet2_core/LaneletMap.h#L579

[ramdort]

I am trying to use findNearest function however I got bad results probably due to some projections problem.
I have

1. converted the opendrive map Town01.xodr to lanelet using commonroad running the following command,
   crdesigner --input-file Town01.xodr --output-file Town01.osm odrlanelet2 according to this it does not perform any coordinate conversions. Now we this 2 lines are from opendrive map

revMajor="1" revMinor="4" name="" version="1" date="2019-04-06T10:38:28" north="2.8349990809409476e+1" south="-3.5690998535156251e+2" east="4.226810576241>
        <!--<geoReference><![CDATA[+lat_0=4.9000000000000000e+1 +lon_0=8.0000000000000000e+0]]> </geoReference> -->
                <!-- this line causes a problem related to projection remove it and keep the below 2 lines -->
            <!-- the below 2 lines avoid that problem when executing the following command oin the terminal -->
            <geoReference><![CDATA[+proj=tmerc +lat_0=5.1000000000000000e+1 +lon_0=1.0000000000000000e+1 +k=1 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs]]></geoRefe>
            <geoReference><![CDATA[+proj=utm +zone=32 +datum=WGS84 +units=m +no_defs]]></geoReference>

2. defined my origin = lanelet2.io.Origin(50.99856538,10.0029222) and then use the UTM projector and then calling findNearst to find the closest lanelets to the origin, I got their distance non sense values

Distance: 4225194.346952304, Lanelet ID: 31183

3. got more confused when I checked the JOSM projection setting and they were also different
4. tried using pyproj to perform specific projections before calling findNearest and same thing I got non sense results as well.

there are 2 main question,
how to define my Origin of the map and how significant it is , and how should i change my procedure to get reasonable results when calling findNearest ?

Thanks

[smaierhofer]

since we are not using the lanelet2 API/tool, I cannot help here.

[ramdort]

I wanna add a few comments. The wrong distance is due to projection error. I have solved this problem by , define the origin and project it and load the projected origin to the load function as the following lines

origin= lanelet2.io.Origin(50.997029,10.000145)
projected_origin = UtmProjector(origin)
lanelet_map_search = lanelet2.io.load(map_path_search, projected_origin) 

which makes this issue closed.
I want to ask if I can specify the type that the function findNearst returns like I want the Lanelet of attribute road not walkway or other attributes ? I used a naive approach of window search of lanelet till findNearts finds the first lanelet of attribute road