Mean Value

In 2D

• \(\displaystyle \omega_i = \frac{\tan(\alpha_{i-1}/2)+\tan(\alpha_i/2)}{\|p_i-p\|} \)

In 3D

• \(\displaystyle \omega_i=\frac{n_i \cdot m}{n_i \cdot (p_i-v)}\)

• \(\displaystyle m=\frac{1}{2} \sum_i \theta_i\,n_i\)