- [Instructor] In Catia, there are two different
types of splines we need to talk about.
First is the generative shape design,
or GSD spline, which you should already
be familiar with.
Next is the 3D curve.
This is a nerves type of spline.
And there's a couple of creation types
we're going to discuss.
There's the through points and control points.
And with these, if you're not picking
any sort of background data,
everything that you do select
is going to default to what's called
a privileged plane.
So if I look at my compass
and I right mouse click on this,
you'll notice that I have a privileged plane
for the XY.
So this means if I start picking out in space,
you'll see those points default to that XY plane.
Again, if I pick a point that's off plane
or an edge or something like that,
then it'll snap to that point.
I'm going to cancel,
I'm going to right mouse click,
change my privileged plane.
Now notice the orientation of the compass has changed.
I'm now looking at my YZ plane
as my privileged plane.
And with that, when I go into my 3D curve,
you'll notice that the points that I select
now default to that plane.
These are the actual through points
that this spline is running through.
If I move this, you'll see the spline changes shape.
If I need to add additional points,
by default, the next point is going to be added
after the last point that I dropped.
So if I pick a point out here,
you'll notice it goes to the next,
or if I need to insert a point somewhere in between,
I can come in here and say insert,
pick the segment, and then specify the location.
This allows me to add more shape
and complexity to that curve.
If I need to remove a point,
I can right mouse click on it.
I can remove this point.
Or I can come over here and specify remove a point,
select the point that I want to get rid of,
and it's gone.
The next curve type is called control points.
So for this curve, when I switch the type,
you'll notice that those points become
those control vertices,
and between those vertices are those halls.
These determine the shape of that curve
but not as the curve passes through those points.
So these are the slopes determined
at each one of those locations,
and the curve is driven by these locations in those shapes.
And it operates in the same fashion
as the through points
as far as being able to insert an additional
control point, and the movement of,
as well as the removal.
Other options that you have in the menu
are to disable geometry detection.
So if I'm drawing something and I have background
data that I don't want to accidentally select,
I can turn this on, and no data will be selected.
Another option I have is hide the previsualization curve.
If I turn this off, it's going to show
that curve, and what this will do
is it'll show me what that curve would look like
if I select the next point.
For this course, I'd like to turn that off
and visualize the curve as it is.