actor.bounding_box.extent has the wrong size

[PatrickPromitzer]

Carla version: 0.9.14 and 0.9.15 OS: Ubuntu 20.04 and 22.04

The bounding box size is not right, if we use the Python API to get the bounding_box of the objects.

We are getting the bounding box with the following script

...
actors = world.get_actors()
object_list = []
for actor in actors:
    if actor.type_id.startswith("sensor."):
        continue
    if actor.type_id in ["spectator", "static.trigger.friction"]:
        continue


    vel_carla = actor.get_velocity()
    vel_temp = [vel_carla.x, vel_carla.y, vel_carla.z]
    actor_transform = actor.get_transform()
    actor_dict = dict(
        translation={"x": actor_transform.location.x,
                     "y": -actor_transform.location.y,  # transformation to right handed coordinate system
                     "z": actor_transform.location.z},
        size={"x": actor.bounding_box.extent.x,
              "y": actor.bounding_box.extent.y,
              "z": actor.bounding_box.extent.z},
        rotation={"roll": actor_transform.rotation.roll,
                  "pitch": actor_transform.rotation.pitch,
                  "yaw": actor_transform.rotation.yaw},
        # transformation to right handed coordinate system
        object_id=20 if len(actor.semantic_tags) < 1 else actor.semantic_tags[0],  # could be more semantic tags
        velocity={
            "x": vel_temp[0],
            "y": vel_temp[1],
            "z": vel_temp[2]},
        object_name=actor.type_id
        )
    object_list.append(actor_dict)

[PatrickPromitzer]

I got a bit deeper into this topic.

At first, the documentation told me that actor.bounding_box.extent.x should be actor.bounding_box.extent.x * 2 After fixing the rotation problem on our side and updating the script, the bounding_box was still not completely right.

I created a mini tool which is using the semantic lidar sensors to get the right size of the carla actors and compared the difference.

Actor amount: 190 (we added 5-10 actors)

max_allowed_difference = 0.1 (meter)
Good bounding box: 102
Bad bounding box: 88

I looked for wrong center points and wrong sizes.

max_allowed_difference = 0.01 (meter)
Good bounding box: 54
Bad bounding box: 136

With the "traffic.speed_limit.50" not having a blueprint, I still need to calculate the traffic objects. (if needed) We can use the calculated Actor information now, but it would be good if Carla has the right data itself.

[PatrickPromitzer]

I got the permission to share the script. calculate_carla_actor_bounding_box.zip

To be able to work, you need a free place with no objects nearby, and only road or ground. (you could spam the actor in the air) I made a small change to be able the change the "actor_transform" where the objects spawn, and select the tags that should be ignored.

[PatrickPromitzer]

I found a bug in my code and created an updated version. The ZIP includes the code, and a json with the calculated bounding box. New version: calculate_carla_actor_bounding_box_v2.zip