Thanks! A very simple but great way to estimate mean curvatures@NathanReed answer. For my case, I also need an estimate of triangular mesh curvature, and I support this is what i was looking for. However, could you please show me (or any recommended literature) how is the following equation derived?
$$\frac{(n_1 - n_0).(p_1 - p_0)}{||p_1 - p_0||^2}$$