I want to know the orientation of each 3D box?

[admyxs]

Excellent work！！！ but I want to know some details.
I want to know the orientation of each 3d box?
For example, if I have a box, I can know the orientation of the front of the vehicle

Like the picture below, given a 3D bounding box of a vehicle, I want to know the orientation of its front, which is very important for calculating AOE in Nuscenes

For example
In the following figure,
If the 3D box has no orientation, the AOE is calculated as 0,
If it has an orientation, the AOE is Pi

[yiyiliao]

Thank you for the question! The short answer is that [1, 0, 0] is the forward-facing direction for all vehicles.

Here are more details. Our XML annotation file provides the following vertices in the object coordinate system as follows:
[[ 0.5, 0.5, 0.5],
[ 0.5, 0.5, -0.5],
[ 0.5, -0.5, 0.5],
[ 0.5, -0.5, -0.5],
[-0.5, 0.5, -0.5],
[-0.5, 0.5, 0.5],
[-0.5, -0.5, -0.5],
[-0.5, -0.5, 0.5]]

These vertices are first scaled and then transformed to the world coordinate system.

In the original object coordinate system, [1, 0, 0] indicates the heading direction of the vehicles. When converting the [1, 0, 0] to the world coordinate system, we obtain the following arrows:

I've updated our kitti360Viewer.py to include the above visualization of the heading directions. You find the updates in this commit.

[admyxs]

I got it!
Thank for your reply!!!