Documentation for overridden members of AdvancingFront class

[haldean]

Hi there! I'm trying to use the AdvancingFront class for a mesh generation task, but I am having a very hard time understanding what my implementation of the Seed and Place virtual methods are meant to do, and the comments in the source code aren't really helping me.

Would it be possible to get more documentation into that file, or at the very least a simple explanation of what each of those methods is meant to do? Thank you so much!