How to reproduce MobilePose v2 result? Which diagonal edge for normalized?

[Learningm]

Hi, I am interested in these amazing work but I wonder how to reproduce mobilepose v2 result.

How to understand the loss 'per vertex MSE normalized on diagonal edge length' ? What do you mean by diagonal edge length? 2D or 3D? I guess it should be 2D because the output keypoints are 2D, but which diagonal edge? We got six faces of the cuboid, 12 diagonal edges of cuboid faces, 2 diagonal edges for 3D cuboid. However, the 2 diagonal edges for 3D cuboid are not equal cause they are projected to the 2D space.

I guess the training pipeline should be:

1. 2D detector training used 2D bbox data
2. use 2D detector (gt or predicted seems both ok) to generate cropping region, and crop the image, adjust the keypoints ground-truth according to the cropping, and use backbone to predict 9 2D keypoints, then compute loss.

Could you explain more details about this part(which diagonal edges)? Thank you very much.