Hi Will,

> Michael, is there a reason why those small line segments
> show up in your models? (Especially since they're not
> usually intentional!)

In this case it was basically a side effect of trying to deal with an inaccurate portion of the model.

If you look at this spot here where these 2 surfaces meet:



You can see there that those surfaces are not tangent with one another, that is a slight kink there where they meet.

Having that kink means that it is harder to make a sweep that follows that as just simple pieces without any juncture between them. But since the kink is pretty small I decided to just delete a curve control point at that spot to smooth out my sweep so it could be just one surface through that spot.

However, doing that causes the sweep to be slightly different in shape in that area from the base surface, and with edge running along the side of it, the edge now doesn't hug right exactly along the surface so when it is cut in the boolean (edges are cut in booleans same as surfaces) it will result in some small pieces.


Here is a zoom in on that area before doing the boolean so you can see how the edge is situated, and why that results in a small fragment after intersections:



Really the best way to avoid this is to ensure a greater accuracy in your original curve structure before building surfaces, so that segments there are set up to be tangent to one another rather than only slightly creased.

Otherwise, any inaccuracies in your original curves tend to become magnified as you try to build more and more stuff hanging off of them. Tangency is especially important for things that involve some kind of offset from them, like fillets, sweeping tubes, etc...

Things that are only off from a few degrees of tangent are not good for the filleter, because it creates kind of micro gap between different fillet segments that the filleter has to try to deal with.

It's a lot easier to solve these issues by taking some care that your initial curve framework is accurate and pieces are not just "eyeballed" to look pretty tangent.

But it also depends on what you are doing, if you are not going to be hanging more things off of that stuff (like fillets, sweeps, etc..) then you can get away with kind of sloppy junctures a little more.

- Michael

Hi, thanks for the explanation - yes, I've run across situations like that and deleting the extra point(s) is usually good enough.


When you put in the object type display (solid, surface, curve etc.,) it gave me a much higher level of confidence when working on my various objects. I knew if I didn't see "Solid", I knew there was a hole in my object somewhere that would cause me problems later.

Little segments like that makes me wish there was a diagnostic tool or a way to highlight little slivers or perhaps have a tolerance that could be set that would avoid adding segments below a certain length to help avoid issues that crop up from things like this.

I guess you really have to be diligent and can't just eye your models like you mentioned.

-Will

Hi Will, yup I have some plans for adding in some other various kinds of diagnostic/analysis tools in the future.


> When you put in the object type display (solid, surface,
> curve etc.,) it gave me a much higher level of confidence
> when working on my various objects. I knew if I didn't see
> "Solid", I knew there was a hole in my object somewhere
> that would cause me problems later.

Yup, that's basically one type of "always on" diagnostic tool right there, really.

It's definitely a great habit to check that thing to see if you've got what you expected (like is it a closed curve, or a solid, or not).


> or perhaps have a tolerance that could be set that
> would avoid adding segments below a certain length
> to help avoid issues that crop up from things like this.

Unfortunately this part would be pretty difficult to handle when things are being intersected with one another.

If the proper result of the intersection would mean little bits are formed, it is hard to think about how to avoid that without doing something like leaving holes in those areas...


But yeah when you're going to hang various further steps off of an initial curve structure, nothing really beats having those initial curves being formed well.

- Michael