- [Instructor] So, where do all the terminologies
from Class A surfacing come from?
Well, it has its basis in nautical terms.
The word, spline, for instance, is a long slat of wood
that was bent into shape to form the hull.
If that long slat of wood isn't long enough,
they would use two slats of wood joined together,
and that joint is called a knot point.
Now, if I look at this surface,
this has an invisible patch.
This patch is a knot point.
This is where two surfaces come together.
And the same is true for curves, our splines.
You don't see this with the naked eye,
mathematically it's in there,
and it's just a part of that surface.
Same thing with a knot point on a curve.
You may not see that knot point.
Part of the goal of a Class A surfacer
is to minimize those knots.
Think of it in terms of using too many boards
or too many planks to make that surface.
You want to minimize those planks,
you want to minimize those boards,
and get the most out of each one of those segments.
Now, how do we control the shape on a surface or a curve?
Well, we have control hulls.
These are called hulls or polylines.
These are called control points or control vertices.
And these actually define the shape
of that surface or curve.
Again, back to shipbuilding.
They would use weights
that represented these control points or hulls,
or they would use pins or something along those lines,
to form that spline or to form that surface
to hold it in place while they affixed it to
the rest of the hull form.
Now, as we look at a surface in our 3D world,
we can see that I have a surface
that's adjoining this surface.
These are two completely different surfaces.
And one way to look at this is
this is an internal patch, this is an external patch.
In other words, these are two separate surfaces altogether,
and they share a common edge.
Now, if I inspect this surface,
you'll notice that it's overbuilt,
just like a spline would be.
You would overbuild everything, get the form,
trim things back, back to the edges that you need,
and then adjoin all of the additional surfaces
that would make up the final form.
So, a lot of what we're doing in Class A surfacing is,
again, based off of how we used to form
ships' hulls or boats.
Those kinds of things.
So, if you really want to get a great understanding
and have a deep history on how things were built,
and how things have come together
to where we're at nowadays,
take a look at our shipbuilders.