- [Instructor] Often times you receive data
from a styling group or you've created something
that you need to change the shape of,
and for that we use a tool called X-form.
X-form allows you to select a surface
and manipulate not only the parameterization,
basically how complex the math is,
but also the shape.
There's several ways you can move the control points
of that surface.
Today we're going to talk about just simply the move tool.
This is what you're going to use more often than not.
Once I have my surface selected,
pole selection is highlighted.
With this I can come in and specify a poly line,
grab it, and move it based off of,
in this case, what's called vector.
So I'll picky my Vector.
My pole selection is set.
And now it's moving along that direction.
I can come in and specify a Normal.
The Normal, again, is based off of the surface normal.
This is going to offset those control points
off of that normal.
The moment I release that row of control polyons,
it's going to align the surface and set up a new normal.
So if you want to move it in the exact same direction
as before, once you do a release,
it's not going to give it to you.
So make sure you get your movement done
just the way you want
and then once you release the new normal is defined.
Another way to move is with polygon.
With this I can specify the entire poly line
and I can use one of these handles, this arrow handle,
and move along the mesh.
So let me rotate it in this direction,
and when I grab one of these you'll see
that it is translating the mesh line
in the direction of the mesh line.
So this is basically forming your vector.
So if I take this one and move it up.
Other things that you can do
with the X-form is control that paramaterization.
That parameterization again is the math,
how much underlying math does the surface have.
The more control points I have,
the more difficult it is to control the smoothness
and ease of movement,
and often times when we get translated data in
we end up with additional patches on the surface.
Patches are those invisible knot lines or knot points
that I talked about.
We want to make sure that we minimize these patches
to basically nothing if we can except
for the original base patch
when we're talking about our primaries.
The simpler the primary surface, the better.
Now when I reduce the number of patches,
you'll see the control points reduce
'cause I'm removing those internal knots,
and I'm creating a deviation back to the base surface.
So in this case I'll have to increase the degree.
As you can see, the higher the degree,
I can get some pretty radical shapes.
So this is one of those things where you have
to make sure you balance everything out.
And now that I have it to something
that gives me a nice smooth flow,
I can begin my manipulation again of my control points.
So as you go through and use the X-form,
often times I use that parameterization tool
to simplify surfaces, clean things up,
move them as I see fit, update the highlight lines,
make sure everything looks good.
Another very useful tool within the X-form
that you need to remember
because if you forget you may actually
cause yourself a little grief later on is the microposition.
So as you're going through and making these manipulations,
let me go to Normal, you may want to move something
just ever so slightly, and as you can see,
this is like a mouse warp.
Right now as I move the mouse, if I move it an inch,
then I'm only moving the control point 5% of that inch.
So this is a great way to fine tune surfaces
and tight little areas again
to make sure you get your flow lines going
just the way you want.