Build subdivisions from curves

00:03

Curves can be used to extrude, sweep and revolve SubD shapes.

00:08

On the shelf, this Curve tool here is set to degree 1

00:12

and that will create straight line polygonal curves.

00:15

And so I can trace this roof shape, for example

00:18

and also specify the SubD layout at the same time.

00:23

So I'll use Extrude first and I'll double-click to open the options

00:27

and I'll need to make sure that the Pick type is set to Curves / Surfaces.

00:33

And then I just extrude with the manipulator

00:36

and the faces are created exactly where my curved segments were placed.

00:41

And the nice thing about Extrude is that I can just hit Extrude Again or space bar

00:45

and continue building up the roof shape.

00:49

And because these second and third extrusions were from the SubD edges,

00:53

they'll be welded together to create a smooth shape.

00:58

Now, I don't have to use a degree 1 curve. I could change the settings here

01:04

or I can use the curve tools on the palette.

01:08

And I like to use the Edit Point Curve which defaults to degree 3.

01:13

So if I want to do this hood, I can just place a start

01:16

and end point

01:18

and then pick and move the interior CVs.

01:21

And I'm going to give it a little bit of an extreme shape here.

01:25

So this time when I use Extrude on this curve

01:29

because it's a smooth curve, it's got to be rebuilt into flat divisions.

01:39

maybe four.

01:41

And then with this uniform mode,

01:43

initially, it's giving me equally spaced faces.

01:47

But because I've got more shape at the front of the curve here,

01:50

I can use this Curvature Bias slider to change

01:53

the spacing to give me a much better match.

01:56

And there's also a Parametric option

01:59

which takes the internal curve structure to define the face spacing.

02:04

But you do need to keep this option window open to make these changes.

02:08

There's no Query Edit History to reopen it

02:12

and there's also no history link with the curve either,

02:15

so changing the curve shape won't update the subdivision.

02:20

So I can have a look at the wheel arch curve now.

02:23

And I can use this Circle tool which defaults to degree 5

02:27

so I'll just take that and place it in the side view

02:30

and scale it up.

02:33

So that's a smooth curve.

02:34

But I can always decide later if I want to change

02:37

it to a polygonal curve by using the Control Panel here

02:40

to put the degree back to 1.

02:44

If I want to remove these lower segments,

02:47

then on the palette, I can use the Object Edit Detach tool

02:51

and use Ctrl-snap on this point and go

02:55

and the same on this one.

02:57

And that separates that part which I can then just delete.

03:03

So then I can move that out to where the wheel arch should be.

03:07

And then I'll just move these bottom CVs inwards a bit

03:12

and then I'll just close the palette

03:14

and I'll use Extrude again.

03:17

And here I have a choice of Normal or Global direction,

03:21

but I'll typically change this on the manipulator.

03:25

So if I switch to Normal here,

03:27

I can grow this SubD

03:29

out nicely from the curve

03:31

and then maybe just move it inwards a bit to create a wheel arch rim.

03:38

Now, if I have a look at the back here,

03:40

I've got some curves I can use with Sweep.

03:44

So I'll open Sweep and I'll start by selecting

03:47

the profile curve or curves here and then Done.

03:52

And then I'll select just a single rail to start with

03:56

and build it.

03:58

And because this was a smooth curve, then I need to choose how many divisions I want.

04:02

So maybe four.

04:05

And if I take a look in the top view,

04:07

you can see that the Parallel mode keeps the profile parallel

04:12

and Radial maintains the angle to the rail.

04:18

So I'll do a Next

04:19

and select this profile.

04:22

And this time I'll use two rails and I've got to be

04:25

careful to select the curve and not the SubD edge here.

04:29

And that then sweeps between those two rails.

04:34

Up at the front, I've got some tire curves that I can revolve

04:38

and I'll just do a Hide Unselected

04:41

and a Look At.

04:44

So this is a degree 3 curve with quite a detailed shape

04:48

and a pivot point here in the center.

04:51

So I'll just use the Revolve tool

04:54

and it defaults to the Z axis

04:57

so I can change that to Y.

04:59

And this Local Pivot setting here uses the curve pivot point as the revolve center.

05:05

So I could change that using Move Pivot before I revolve

05:10

or in my case,

05:11

I can use the Global option because the wheel is centered on the grid axes

05:18

and I've got a bit of zig-zagging here

05:20

so I can change any of these settings. So I'm gonna use the Curvature Bias

05:25

and I often find that just below one gives the best result

05:30

and you can have a look at the limit surfaces to refine that further.

05:35

So then I can do the other curve as well to complete the tire.

05:43

So curves are a useful way to get started with your initial SubD shapes.

Video transcript

00:03

Curves can be used to extrude, sweep and revolve SubD shapes.

00:08

On the shelf, this Curve tool here is set to degree 1

00:12

and that will create straight line polygonal curves.

00:15

And so I can trace this roof shape, for example

00:18

and also specify the SubD layout at the same time.

00:23

So I'll use Extrude first and I'll double-click to open the options

00:27

and I'll need to make sure that the Pick type is set to Curves / Surfaces.

00:33

And then I just extrude with the manipulator

00:36

and the faces are created exactly where my curved segments were placed.

00:41

And the nice thing about Extrude is that I can just hit Extrude Again or space bar

00:45

and continue building up the roof shape.

00:49

And because these second and third extrusions were from the SubD edges,

00:53

they'll be welded together to create a smooth shape.

00:58

Now, I don't have to use a degree 1 curve. I could change the settings here

01:04

or I can use the curve tools on the palette.

01:08

And I like to use the Edit Point Curve which defaults to degree 3.

01:13

So if I want to do this hood, I can just place a start

01:16

and end point

01:18

and then pick and move the interior CVs.

01:21

And I'm going to give it a little bit of an extreme shape here.

01:25

So this time when I use Extrude on this curve

01:29

because it's a smooth curve, it's got to be rebuilt into flat divisions.

01:39

maybe four.

01:41

And then with this uniform mode,

01:43

initially, it's giving me equally spaced faces.

01:47

But because I've got more shape at the front of the curve here,

01:50

I can use this Curvature Bias slider to change

01:53

the spacing to give me a much better match.

01:56

And there's also a Parametric option

01:59

which takes the internal curve structure to define the face spacing.

02:04

But you do need to keep this option window open to make these changes.

02:08

There's no Query Edit History to reopen it

02:12

and there's also no history link with the curve either,

02:15

so changing the curve shape won't update the subdivision.

02:20

So I can have a look at the wheel arch curve now.

02:23

And I can use this Circle tool which defaults to degree 5

02:27

so I'll just take that and place it in the side view

02:30

and scale it up.

02:33

So that's a smooth curve.

02:34

But I can always decide later if I want to change

02:37

it to a polygonal curve by using the Control Panel here

02:40

to put the degree back to 1.

02:44

If I want to remove these lower segments,

02:47

then on the palette, I can use the Object Edit Detach tool

02:51

and use Ctrl-snap on this point and go

02:55

and the same on this one.

02:57

And that separates that part which I can then just delete.

03:03

So then I can move that out to where the wheel arch should be.

03:07

And then I'll just move these bottom CVs inwards a bit

03:12

and then I'll just close the palette

03:14

and I'll use Extrude again.

03:17

And here I have a choice of Normal or Global direction,

03:21

but I'll typically change this on the manipulator.

03:25

So if I switch to Normal here,

03:27

I can grow this SubD

03:29

out nicely from the curve

03:31

and then maybe just move it inwards a bit to create a wheel arch rim.

03:38

Now, if I have a look at the back here,

03:40

I've got some curves I can use with Sweep.

03:44

So I'll open Sweep and I'll start by selecting

03:47

the profile curve or curves here and then Done.

03:52

And then I'll select just a single rail to start with

03:56

and build it.

03:58

And because this was a smooth curve, then I need to choose how many divisions I want.

04:02

So maybe four.

04:05

And if I take a look in the top view,

04:07

you can see that the Parallel mode keeps the profile parallel

04:12

and Radial maintains the angle to the rail.

04:18

So I'll do a Next

04:19

and select this profile.

04:22

And this time I'll use two rails and I've got to be

04:25

careful to select the curve and not the SubD edge here.

04:29

And that then sweeps between those two rails.

04:34

Up at the front, I've got some tire curves that I can revolve

04:38

and I'll just do a Hide Unselected

04:41

and a Look At.

04:44

So this is a degree 3 curve with quite a detailed shape

04:48

and a pivot point here in the center.

04:51

So I'll just use the Revolve tool

04:54

and it defaults to the Z axis

04:57

so I can change that to Y.

04:59

And this Local Pivot setting here uses the curve pivot point as the revolve center.

05:05

So I could change that using Move Pivot before I revolve

05:10

or in my case,

05:11

I can use the Global option because the wheel is centered on the grid axes

05:18

and I've got a bit of zig-zagging here

05:20

so I can change any of these settings. So I'm gonna use the Curvature Bias

05:25

and I often find that just below one gives the best result

05:30

and you can have a look at the limit surfaces to refine that further.

05:35

So then I can do the other curve as well to complete the tire.

05:43

So curves are a useful way to get started with your initial SubD shapes.

Video quiz

Required for course completion

To remove segments from a polygonal curve, before selecting the CVs at each end point, you should select which of the following commands?

(Select one)
Select an answer

1/1 questions left unanswered

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