Fig. 5From: Deep 3D mesh watermarking with self-adaptive robustnessThis is a 3D model of a desk. In the bottom right figure, the desktop is flat and the normal vector \({\mathbf {n}}_i\) is perpendicular to the local area. For each \(j\in {\mathcal {N}}_i\), \(\theta _{ij}=90^{\circ }\). The bottom left figure and the top right figure are the convexity and concavity of the the desk respectively, with \(\theta _{ij}>90^{\circ }\) and \(\theta _{ij}<90^{\circ }\)Back to article page