> I need to identify the sharp edges (i.e. polygons which create edges
> with sharp angles by taking dot product of normals) and store the
> coordinates of their vertices. Could anyone help me with this
Not unless you more clearly define where, in this procedure, your
problem is. The task is really simple, assuming you have those
polygons described by an appropriate data structure. Just iterate over
it, check, and write out the list of results. To help more precisely,
we need to know details about your data structure, and what the
exact problem is you're having with it.
Even if all the snow were burnt, ashes would remain.