the surface, therefore the radius $R$ should be kept small with respect to the overall dimension of the surface. This implies that the choice of the radius $R$ is crucial for the type (and the size) of the patterns we are going to identify; indeed it must be not too large to avoid to mix global and local surface information and not too small to become insignificant. In practice, the multiply connected regions appear in case of topological noise, like small handles and mesh self-intersections; in our experiments over thousands of tessellations we never met meaningful admissibility problems.

We opt for a uniform distribution of the ring radii values. Denoting $R_{max}$ the maximum radius and $N_r$ the number of rings, the value of the ring radii will be $\frac{R_{max}}{N_r}, 2\frac{R_{max}}{N_r}, \ldots, R_{max}$.

                Base models                                                                 Textured models                                                                                           
  --------------------------------------- -------------------------------------- -------------------------------------- -------------------------------------- -------------------------------------- ----------------------------------------
                                                         Class 1                                Class 2                                Class 3                                Class 4                 
   ![image](pic/mod1.png){width="1.4cm"}   ![image](pic/pt1.png){width="1.4cm"}   ![image](pic/pt2.png){width="1.4cm"}   ![image](pic/pt3.png){width="1.4cm"}   ![image](pic/pt4.png){width="1.4cm"}   ![image](pic/cmod1.png){width="1.4cm"}
                                                         Class 5                                Class 6                                Class 7                                Class 8                 
   ![image](pic/mod2.png){width="1.4cm"}   ![image](pic/pt5.png){width="1.4cm"}   ![image](pic/pt6.png){width="1.4cm"}   ![image](pic/pt7.png){width="1.4cm"}   ![image](pic/pt8.png){width="1.4cm"}   ![image](pic/cmod2.png){width="1.4cm"}
                                                                                                                                                                                                      
                                                                                                                                                                                                      

Similarity assessment {#ss:descriptor}
---------------------

Once the function $h$ is evaluated over the sample sets of the rings around $v$, the edgeLBP value on $v$ straightforwardly follows from the classic LBP 