Impossible to get the pedestrian crossings on the map

[dx6nxr]

System Details

1. Python ver.: 3.8.10
2. Scenic ver.: 3.0.0b2
3. OS: Intel / Win 11
4. Simulation in carla

Detailed Description

1. When trying to extract all of the pedestrian crossings on the map, none are returned, doesn't matter if I try to get them from the intersections or the roads. I.e. if I try to get all the roads where crossings are not an empty tuple, roads = filter(lambda i: i.crossings != (), network.roads), and assert that list is not empty, I get the assertionError. I checked the .xodr file of the Town05 map, and it has multiple Crosswalks (exact number is 66). Code is as follows:

param map = 'assets/maps/CARLA/Town05.xodr'
param carla_map = 'Town05'
param time_step = 1.0/10

model scenic.simulators.carla.model

roads = filter(lambda i: i.crossings != (), network.roads)

assert len(roads) > 0, \
    'No roads with crossings found in the network'

2. scenic -S --2d --count 1 ..\ScenicToOSC\scenic\scenarioUnexpectedPedestrianOnIntersection.scenic -b

pygame 2.5.2 (SDL 2.28.3, Python 3.8.10)
Hello from the pygame community. https://www.pygame.org/contribute.html
Loading cached version of road network...
Loaded cached network in 0.36 seconds.
Traceback (most recent call last):
File "C:\Users\ivbu01\AppData\Local\Programs\Python\Python38\lib\runpy.py", line 194, in run_module_as_main
return run_code(code, main_globals, None,
File "C:\Users\ivbu01\AppData\Local\Programs\Python\Python38\lib\runpy.py", line 87, in run_code
exec(code, run_globals)
File "C:\venv1\Scripts\scenic.exe_main.py", line 4, in
from scenic.main import dummy
File "C:\Scenic\src\scenic_main.py", line 195, in
scenario = errors.callBeginningScenicTrace(
File "C:\Scenic\src\scenic\core\errors.py", line 282, in callBeginningScenicTrace
return func()
File "C:\Scenic\src\scenic_main.py", line 196, in
lambda: translator.scenarioFromFile(
File "C:\Scenic\src\scenic\syntax\translator.py", line 142, in scenarioFromFile
return _scenarioFromStream(
File "C:\Scenic\src\scenic\syntax\translator.py", line 172, in _scenarioFromStream
compileStream(stream, namespace, compileOptions, filename)
File "C:\Scenic\src\scenic\syntax\translator.py", line 321, in compileStream
executeCodeIn(code, namespace)
File "C:\Scenic\src\scenic\syntax\translator.py", line 560, in executeCodeIn
exec(code, namespace)
File "C:\ScenicToOSC\scenic\scenarioUnexpectedPedestrianOnIntersection.scenic", line 12, in
assert len(roads) > 0,
AssertionError: No roads with crossings found in the network```

Steps To Reproduce

1. Just running the code on any map is enough to reproduce the problem.

param map = 'assets/maps/CARLA/Town05.xodr'
param carla_map = 'Town05'
param time_step = 1.0/10

model scenic.simulators.carla.model

roads = filter(lambda i: i.crossings != (), network.roads)

assert len(roads) > 0, \
    'No roads with crossings found in the network'

Issue Submission Checklist

• I am reporting an issue, not asking a question
• I checked the open and closed issues, forum, etc. and have not found any solution
• I have provided all necessary code, etc. to reproduce the issue

[dx6nxr]

I dig into the code a bit, and found out that crossings are only initialized to () in the Road class when initializing the road itself, and never added after, thus no wonder this doesn't work.
crossings: Tuple[PedestrianCrossing] = () from scenic/domain/driving/roads.py line 431.

[dfremont]

Hi Ivan, you're right, our OpenDRIVE parser currently does not extract information about pedestrian crossings (OpenDRIVE objects of type "crosswalk"). If you want to try implementing that functionality, we'd be happy to advise (you can make a post on our new forum if you like); otherwise, it's not a priority for us at the moment but we can try to take a look some time this year.

[dx6nxr]

Hey @dfremont,
I will try to implement it on my own. Only question I have considering the map caching, where does scenic store the parsed opendrive maps? Bcs I need to delete old map caches in order for it to parse them again with extended code. Thanks for the quick answer!
Best, Ivan

[dfremont]

The cached maps are saved in .snet files next to the original .xodr files. You can also add the line param map_options = {"useCache": False} to your Scenic program to disable reading the cached versions automatically.

[dx6nxr]

Thank you!

[dx6nxr]

Hey,
Just wanted to share what I was able to do and ask a question considering the positioning of the crosswalks. On the image one can see that crosswalk's geometry is being parsed (in green), but I cannot figure out how do I give them the correct position. As crosswalk is of a type NetworkElement, i guess I should somehow give it orientation when initializing it, but I am confused as whether it is the correct solution, and if it is, then what .xodr parameters do u use for orientation. Thanks!

[dfremont]

The orientation attribute of NetworkElement isn't the orientation of the element itself: it's a vector field giving a preferred orientation to objects placed in the region (lanes for example have a preferred orientation which is given by the direction of traffic). You could simply ignore the orientation attribute to start with.

The position of the crosswalk is given by its polygon property, which should be a Shapely Polygon or MultiPolygon. I haven't looked to see how crosswalks are represented in OpenDRIVE, but you'll need to extract global XY coordinates for the vertices of the crosswalk and build a Polygon from that. In xodr_parser.py we have code which does this for roads, lanes, sidewalks, etc. starting from their reference line and width data in an OpenDRIVE file (mainly Road.calc_geometry_for_type; the resulting polygons are used in Road.toScenicRoad to create Scenic Lane, LaneSection, Sidewalk, etc. objects). You might be able to adapt that code, although the documentation is minimal.