Hi Matt & Martin - I'm still a bit confused now about what should be considered an "exterior" or "outer" edge.

I think I see that what I was thinking previously about it being silhouettes doesn't seem to be quite right - they seem to be silhouettes but it looks like only some silhouettes are considered exterior and others aren't.

In order for these to be categorized by MoI I need to be able to make some kind of quantifiable way to categorize these things, I can't rely just on human judgement.

So one thing that has me confused right now is in Matt's insect walking PDF above, this is shown as the exterior edge:





In the one Martin posted, this one is shown as the accented edge:





So to me it seems as though those are 2 different choices, the first one is the longer one on the top surface, while the second one is the short one on the bottom side...



As far as silhouettes go, there are these 2 different silhouettes for that hole:






Right now I don't understand how I should distinguish between these to pick just one of them as the exterior edge.

Thanks,
- Michael