[Code] Questions on the loss details about meshtransformer HOT 2 CLOSED

Thanks for pointing out the questions!

Q&A1: Sorry for the inconsistent descriptions in the paper/code. When we implement the loss functions, we mainly adopt the loss functions from GraphCMR (CVPR 2019). As the authors (CVPR 2019) discussed in their paper, they empirically found L1 loss gives more stable training compared to MSE loss. However, in their implementation, they actually use MSE loss for the 2D/3D joints, and L1 loss for the 3D vertices. Probably replacing MSE with L1 could further improve our training, but we haven't tried it.

Q&A2: In line 207-211, we are trying to prepare GT data, and we normalize 3D GT joints based on a pre-defined pelvis. When we compute loss in line 125-128, we want to make sure both prediction and ground truth are in the same 3D space, so we normalize them again based on their pelvis (which is computed on the fly by (left_hip+right_ hip)/2).

from meshtransformer.

Thanks for the detailed explanation about my questions!
I greatly appreciate your help :)

from meshtransformer.