Update lib/dataset/mesh_util.py

Fix a important bug which may lead to wrong normal vec

lib/dataset/mesh_util.py

@@ -401,6 +401,7 @@ def cal_sdf_batch(verts, faces, cmaps, vis, points):
                :, None]).sum(1).unsqueeze(0).ge(1e-1)
     pts_norm = (closest_normals*bary_weights[:, :, None]).sum(
         1).unsqueeze(0) * torch.tensor([-1.0, 1.0, -1.0]).type_as(normals)
+    pts_norm = F.normalize(pts_norm, dim=2)
     pts_dist = torch.sqrt(residues) / torch.sqrt(torch.tensor(3))
 
     pts_signs = 2.0 * (check_sign(verts, faces[0], points).float() - 0.5)