Add crown shape to models

00:01

The Skin tool has this Crown Mode option,

00:04

and this becomes available once we've built the skin surface.

00:08

If I turn on the CVs,

00:10

you can see that a default skin creates a straight line ruled surface.

00:15

But when I add some crown, I get this extra row of CV S in the middle

00:19

which creates this arc shape.

00:22

And I can work with this either in the model

00:24

window by flipping the crown or adjusting the value of it

00:30

or over here in the control window.

00:33

And here I've also got a Crown Position slider

00:36

and this will adjust the position of that center row

00:38

of CVs to nudge the shape up or down.

00:42

And to explain Proportional and Absolute,

00:45

I'm gonna switch to this simpler example here.

00:48

If we use Proportional, then this crown value determines a crown height,

00:53

that's always going to be a proportion of the width of the skin surface

00:58

With Absolute, that crown value is just the distance in model units.

01:03

So here I've just got exactly five mm

01:05

for the height.

01:08

But this really only makes a difference

01:10

if the width of the skin varies along its length.

01:16

So here you can see the Proportional is

01:18

maintaining a more consistent cross section shape.

01:25

So finally, I'll have a look at this roof surface

01:28

and

01:29

I'll apply some crown.

01:33

And, it may be that I don't want this pure arc shape.

01:37

And so here I have the Crown Shape value, and as soon as it goes away from one,

01:42

you can see that it creates

01:44

an extra row of CVs to create a degree-3 surface

01:47

and I can change the position of those CVs.

01:50

And that allows me to create a more peaky surface

01:54

or one with the curvature pushed outwards,

01:56

which is more typical for an automotive centerline surface.

02:00

And if I type a value of 1

02:02

and I get that back to a degree-2 surface.

02:05

Now, the Freeform Blend tool when it's set to Position and to Position

02:10

also has the option of this Crown Mode and it works in exactly the same way.

Video transcript

00:01

The Skin tool has this Crown Mode option,

00:04

and this becomes available once we've built the skin surface.

00:08

If I turn on the CVs,

00:10

you can see that a default skin creates a straight line ruled surface.

00:15

But when I add some crown, I get this extra row of CV S in the middle

00:19

which creates this arc shape.

00:22

And I can work with this either in the model

00:24

window by flipping the crown or adjusting the value of it

00:30

or over here in the control window.

00:33

And here I've also got a Crown Position slider

00:36

and this will adjust the position of that center row

00:38

of CVs to nudge the shape up or down.

00:42

And to explain Proportional and Absolute,

00:45

I'm gonna switch to this simpler example here.

00:48

If we use Proportional, then this crown value determines a crown height,

00:53

that's always going to be a proportion of the width of the skin surface

00:58

With Absolute, that crown value is just the distance in model units.

01:03

So here I've just got exactly five mm

01:05

for the height.

01:08

But this really only makes a difference

01:10

if the width of the skin varies along its length.

01:16

So here you can see the Proportional is

01:18

maintaining a more consistent cross section shape.

01:25

So finally, I'll have a look at this roof surface

01:28

and

01:29

I'll apply some crown.

01:33

And, it may be that I don't want this pure arc shape.

01:37

And so here I have the Crown Shape value, and as soon as it goes away from one,

01:42

you can see that it creates

01:44

an extra row of CVs to create a degree-3 surface

01:47

and I can change the position of those CVs.

01:50

And that allows me to create a more peaky surface

01:54

or one with the curvature pushed outwards,

01:56

which is more typical for an automotive centerline surface.

02:00

And if I type a value of 1

02:02

and I get that back to a degree-2 surface.

02:05

Now, the Freeform Blend tool when it's set to Position and to Position

02:10

also has the option of this Crown Mode and it works in exactly the same way.

Video quiz

Required for course completion

When adding a crown shape to the surface of a model, which of the following Crown options really only makes a difference if the width of the skin varies along its length?

(Select one)
Select an answer

1/1 questions left unanswered

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