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The devkit of the nuScenes dataset.
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Stop Line Interpretation #1089

Open SaraMo14 opened 1 week ago

SaraMo14 commented 1 week ago

Hi,

I have some doubts about the NuScenes MapAPI.

  1. What does the stop line type 'TURN STOP' represent and why is it under the record 'ped_crossings'?

  2. Except for the traffic light which has an orientation, how do I tell if the other stop line types (STOP_SIGN, YIELD, PED_CROSSING, etc) are oriented toward the ego vehicle or not? Some of them offer road_segment and road_block information, but is this enough?

Thanks!

whyekit-motional commented 1 week ago

  1. I believe TURN_STOP is used for pedestrian crossings which are at turns

  2. A line, by definition, does not have a direction (in contrast, a traffic light has an orientation denoted by the direction in which its set of bulbs are facing)

SaraMo14 commented 1 week ago

Hi,

thank you for the answer! For 1), this is a plausible answer, however most of the time if I check the stop line of type 'TURN_STOP', there is no ped_crossing token. For example: {'token': '04baaab2-94a5-4734-89a6-113ef5861d75', 'polygon_token': '78bd8693-014f-4bcb-afb1-32cfffd9d3d6', 'stop_line_type': 'TURN_STOP', 'ped_crossing_tokens': [], 'traffic_light_tokens': [], 'road_block_token': '', 'exterior_node_tokens': ['6d88e398-7ef2-4962-a96e-0296ff7eed86', 'e1a7b327-fad1-4b80-bee3-cb592984d276', 'b63cd317-b048-419d-9f93-c5412cd69e86', 'f1496b72-5a11-48a9-9bb6-cae29cbb34e1', '37a286ec-6e56-4e9d-81cf-3b4c92de2e76', '71890aeb-93c6-4983-843e-722824205cea', '75fd19cb-5f3a-44e9-9478-b0cf46a754b3'], 'holes': [], 'cue': []}

For 2), this is true for PED_CROSSINGs, but for example STOP_SIGNs should have an orientation.

whyekit-motional commented 1 week ago

  1. Pls take a look at the maps tutorial:

    ped_crossing_tokens denotes the association information if the stop_line_type is PED_CROSSING.

    That is why TURN_STOP does not come with ped_crossing_tokens

  2. In nuScenes, I think a stop sign is treated the same as a stop line, in that it is not given an orientation