[###updated for new question] 关于旋转角 变换的困惑，求帮助

[xzswater]

[###updated for new question] 关于旋转角 变换的困惑，求帮助

[sshaoshuai]

We have the following definitions:

1. The LiDAR coordinate denotes the KITTI LiDAR coordinate system, with x: forward, y: left, z: up, and the direction of zero orientation is along the -y.
2. The local coordinate denotes the coordinate system of a object, with x: heading direction of this object, y: perpendicular to x, z: up, and the direction of zero orientation is along the x.

Hence, for transforming the LiDAR coordinate to local coordinate, we should rotate the object points with ry + np.pi / 2

[xzswater]

@sshaoshuai Thank you very much ! And, could you help to explan why dir_offset set to pi / 4 ?

tools/cfgs/PartA2.yaml

pcdet/utils/box_coder_utils.py

[penghao1990]

您好，请问为什么需要dir_offset，并且设置为pi/4呢？我不明白，能否帮助一下。谢谢！

[DeclK]

I found someone else's answer might solve this question