Function triangle_area

src/losses.py:8–13

(v, f)

import pytorch3d

def triangle_area(v, f):
    A = torch.gather(v, 0, f[:, 0].unsqueeze(-1).expand(-1, 3))
    B = torch.gather(v, 0, f[:, 1].unsqueeze(-1).expand(-1, 3))
    C = torch.gather(v, 0, f[:, 2].unsqueeze(-1).expand(-1, 3))
    normal = torch.cross((B - A), (C - A), dim = -1)
    return normal.norm(p = 2, dim = -1)

def normal_loss(src_meshes, def_meshes):
    N = len(src_meshes)