New Skin tool

In this release, we added an enhanced Skin tool to the Surfaces palette. The enhanced Skin tool has all the capabilities of the original Skin tool, but also includes the following features:

Ability to select a set of curves with G1 continuity to define a single curve set input.
Chain selection, to simplify the selection of G1 adjoining curves in a curve set.
A manipulator handle to define the extent of each curve set.
Proportional Crown option that lets you define the height of the surface above or below the ruled surface between two defined curve sets.
Ability input multiple curves sets to "loft" a surface.
An option to redefine the construction of a surface through Explicit Control.
Initial surface fitting that is based on the curve set with the most complex parameterization (to meet the tolerance) .
Output surfaces are grouped under the Skin node.

NoteThe original Skin tool remains in Alias 2013 but may be removed in a future release.

Basic Workflow

Choose Surfaces > VSR Skin .
The Skin Control box opens.
Click the first curve or curve set to select it.
If Chain Select is on, G1 continuous curves are selected.
Click the next curve or curve set.
To remove the curve or curve set from the selection, click the curve again.
Click additional curves or curve sets to add them.
Click Build.
The surface is created based on the parameterization of the first selected curve.

If Modify range is selected, arrow manipulators appear on the skin surface at each curve or curve set.

If you select a curve or curve set, the selection is removed from the input and the surface is recreated.

Optional deviation displays between input curves and the surface.

Degree and spans of the surface are displayed in numerical fields of the Explicit control option is selected.

If you modify explicit control degree and/or spans, the surface is refit to a new parameterization and the deviation display is updated.

If you modify the location of the range manipulator, the surface is fit to the new extent and the deviation is displayed between the extent of the surface and input curves.

If you select Undo All, the surface is removed.

If you select Next, you are prompted to select the first curve or curve set.

Skin Control Options

Proportional Crown: Select his option to raise the midpoint of the surface between two input curve sets so that the height or crown of the surface is proportional to the distance between the curves. This option is not available when more than two curve sets are selected.
Explicit control: Select this option to specify the exact degree and number of spans in the new surface(s).

Explicit Control Options

These options are availably only when Explicit Control is selected.

U/V Degree: The degree of the new skinned surface in the U and V directions. Values range from 1 to 7.
U/V Spans: The number of spans for the skin surface in the U and V direction.

Flow Control

Start/End: Defines the extent of the surface through a snapping point on each input curve set. You can define the range manipulator snapping points to be at the following locations:

Default – The extent of the surface is defined as the closest point from one curve set endpoint to the second curve set. This maintains the control layout "normal to curve sets.

Extend – The end of the surface can be extended to match the endpoint of the opposite surface. This also maintains the control layout "normal" to curve sets.

Connect ends – The endpoint of the initial curves set is connected to the endpoint of the second curve set. This is the default construction.
Modify range: Select this option to use range manipulators to define a portion of each curve set as input for the surface.

Surface Structure

Surface type: Single surface – A single skin surface is built.

Multiple surfaces – A separate surface is created for each of the input curves you selected, and the surfaces are grouped.
Bezier surfaces: This option only appears if Surface Type is set to Multiple surfaces. If it is selected, each surface will be a Bézier patch.

Bézier patches have a single span, and their maximum degree in the U direction is set through the Explicit Control section.
Short Edge Tolerance: In the case of cross-knot insertion, the system will not allow spans of a length smaller than the Short Edge Tolerance.
Topology: Open – Leave the resulting surface open.

Closed – Connect the first curve to the last curve to create a closed (periodic) surface.

Control Options

Auto update: Automatically update the surface as curves are added.

Create history: Save the history of the new surface for later editing. If you turn Create History on, when you modify the curves that were used to create the surface, the surface updates.

Continuity check: Select this option to see the level of continuity between the newly created surface(s) and the original surface(s).

P – Positional continuity

T – Tangent continuity

C – Curvature continuity

Deviation: Select this option to display the maximum deviation indicator (displays only if Deviation is not 0).
Chain select: If this option is selected, selecting a surface curve also selects all other surface curves that are tangent continuous with it.