- [Instructor] Next tool I want to talk about
is a tool called Extend.
And what this is for is taking curves and surfaces
and making them larger.
So I'll select the surface,
and it sets these nodes up on the four sides of the surface.
What this does for me is it allows me
to grab that node and drag the surface.
You can see I can make it smaller as well, and larger.
And it keeps the shape of the surface
as we make things bigger or smaller.
I can do the same thing with curves.
Now notice that this curve has no history.
This is a NURBS curve that doesn't remember
its parameterization.
It knows that it has control points,
it knows that it was constructed,
it knows it has all that math,
but it doesn't have the parameters of the points
that initially were used to create it.
So when I modify this curve,
it allows it to modify simply without any issue.
If I want to extend something,
whether it's a curve or a surface that has history,
in this case like this 3D curve,
this will happen with the surface as well.
It's going to pop up with this information window
saying I can't extend this element
but I'm going to create a new element,
and the feature result cannot be modified.
Basically, this means that it's not going to
have history to anything.
So if I modify the initial 3D curve,
the new extended curve is not going to remember that.
It's not going to have that history.
So I'll select OK, drag this out,
drag this out, select OK again,
and here's that 2D curve.
So if I were to make a modification to this 3D curve,
you can see that there's no historical link,
no updates, no nothing back to it
because the new curve that's generated off of it
basically copies it, takes that math,
and makes it a non-parametric or unlinked copy.