The normal is flipped

[ne1114]

Hello while experimenting I am facing weird behavior and would like to ask for tips.

When training, the normal vector of the generated mesh gets flipped.

So like in 20th epoch, the normal vector is facing outwards, however around 40th epoch the normal vector starts becoming "noisy". And in 40th epoch the normal vector get completely flipped so facing inwards.

Have you guys encountered this kind of phenomenon ? Could I get a tip on what may be causing this issue please?

[ne1114]

20th

40th

60th

The image is taken from the same camera position. Note the normal is changing. This alternating normal keeps happening throughout the training process.

[Xuanmeng-Zhang]

Hi @ne1114 Could you please provide more details? Which dataset are you using? Could you please show me the real images?