Hi Neil, I mean the ending directions aren't actually tangent there. Just like this example isn't smooth here:



In this example here it's much more obvious that there is a sharp corner. In your cases it's not so obvious because it's only like 3 degrees off from being smooth. That doesn't sound like much but for filleting it can be bad to have shallow corners like that. The reason why is that different fillet pieces will only naturally match each other at smooth spots. At spots that aren't smooth they have to be extended and intersected or have a corner patch made for them. But when it's a shallow angle it tends to make situations like the corner junctures being really small slivery bits which don't behave so well.

Sounds like it isn't a big problem for your case here but the upshot is that it's good for filleting to make your original curve pieces fully tangent to each other in spots like that and not just pretty close to being tangent.

- Michael