- Another modifier that's very commonly
used in spline modeling is called sweep.
It will allow you to create a three dimensional object
from a simple spline curve by sweeping
some profile or some section along that curve.
In this case, I've got a wall ornament
that I'm going to place on my building.
And I've got two elements to that,
one is the path and that's represented here
by this rectangle or diamond shape,
and then the section or profile is this arrow shape.
I'm going to sweep the arrow shape along this path
to create a more complicated 3D surface.
Select that diamond shape or rectangle,
go into the modify panel and it's an editable spline
but it could be any shape such as primitive.
Let's apply the modifier,
click on the modifier list pull down
and we could scroll down to sweep,
or we could also just type in sw on our keyboard
and that'll take it directly to sweep.
Click on sweep and that's applied.
And with the default settings,
we get a built in section or profile that has an angle shape
and let's orbit or tumble around with alt and middle mouse
take a look at this.
They get a little bit easier to visualize
the level of detail by enabling edge faces
which is F4 on your keyboard.
And also I'm going to hide the grid
because they don't really need to see that right now.
There's a keyboard shortcut
to toggle the display of the grid
in the current viewport and that is g.
So now we can see the level of detail quite clearly.
We can change a whole bunch of parameters in here
such as we've got length and width
that's going to change the shape of the profile or section.
And we've got lots of fun stuff in here
like we can even create, you know,
filleted corners by adjusting
these corner radius parameters and so on.
We can also offset that profile or section curve
relative to the path curve in a bunch of different ways.
We can adjust these offset values here manually.
Okay, I'll undo that with control + Z.
I can also use these alignment buttons
these are handy to, for example,
send that section or profile curve
to the interior or the exterior of the path curve.
For example, I could click here
and that'll send the profile curve
so that it's completely enclosed within the path
or I could click on this button over here,
that's going to send a profile curve
to the outer border of that underlying path curve.
All right, now let's talk about level of detail.
You'll see there's an interpolation rollout
in this sweep modifier,
and it's just like the interpolation settings
we saw earlier in the course,
when we looked at interpolation for splines.
Same exact controls here optimizes on by default.
If we turn that off then we won't see the optimization
straight line segments will be subdivided.
Okay, and that can increase or decrease the number of steps.
Bring down we'll have a low level of detail.
I'm going to back up to let's say six.
Now this is going to apply
to one dimension of our swept surface.
We can see that as we increase or decrease
the number of steps we're changing the number of lines
running in just one direction here.
We could kind of think of those as lines of longitude
that are running sort of parallel to the path.
Okay, if we wanted to change the level of detail
running in the other dimension,
we would need to access the interpolation controls
for the underlying path curve.
And we can just go into the editable spline here,
and let's enable show end results
so we can see what we're doing.
And in the interpolation rollout for the editable spline
in order to see our changes, let's disable optimize.
And now we have a whole bunch of lines
running the other direction.
We could think of those as lines of latitude
and we can increase or decrease the level of detail there
by changing the number of steps.
Okay, so that's how to change
level of detail in both dimensions.
Let's go back up to our sweep modifier,
we can also choose different built in sections.
Instead of an angle
we could choose, for example
bar or a cylinder or channel and so on.
So those are all the builtin sections
but I've got a custom section or a custom profile.
So let's choose that click to use custom section
and then we'll need to pick
the custom section in our viewport.
We got a button here pick
and then click on that profile curve,
it's labeled ornament profile.
Now that's been applied as our custom profile or section
we can orbit around with alt and middle mouse button
take a look.
All right, now that looks pretty clean.
And it's because I've chosen
my alignment of the pivot over here to be outside the curve
just to illustrate if I tumble or orbit around here
if we had the default of centering on the path,
then we would actually see
some corrupted geometry or overlapping geometry.
And if we chose to align to the interior of the path
it would be even worse starting to see some
what's called Z fighting here
where sort surfaces are superimposed
and the viewport renderer doesn't really know
what's in front of what and it gets really confused
and this is garbage geometry so we don't want that.
We want to set this back so that
the profile or section curve is in
the exterior of the path curve
and we don't have any geometry issues there.
Now if we want to adjust the interpolation for our new
custom profile or custom section,
we would need to select that object
and adjust its interpolation settings.
And that would be reflected in our sweep modifier
because when we picked our custom section,
we didn't change the default option of instance.
So this profile curve here is actually instant
into this sweep object.
So let's illustrate if I select
that profile curve or even profile,
go into its interpolation rollout and disable optimize.
Now we can see that we're getting
some segmentation here that we didn't have before
and we can adjust the number of steps.
So that's how we can adjust a level of detail
for a custom section or custom profile.
All right, that's how to use a sweep modifier
to sweep a profile along a path.