Tool Palettes Surfaces > Multi-Surface blend > Freeform blend > Control Options

Surfaces > Multi-Surface blend > Freeform blend

Previously called Freeform fillet, Freeform blend enables you to create a transitional surface based on two input contact lines.

See Create a fillet surface

See Choose the type of a fillet surface

See Create a blend surface by specifying profiles.

The Freeform blend tool offers two tabs of options: Simple and Advanced.

The Simple tab restricts the options displayed to Continuity and Shape, as well as the Control Options. All options are available under the Advanced tab.

Continuity

This pop-up menu determines the type of continuity that will be used to create the blend surface.

Tangent: End points plus the end tangents match at the common endpoint.

Curvature: End points, plus the end tangents, plus the curvature of the two curves all match at the common end point.

Span Placement

This pop-up menu controls how the new blend surface is divided into spans.

One-Per-Boundary: Inserts a span corresponding to boundaries between the original surfaces, plus the minimum number of spans needed to meet tangent or curvature requirements.

Free: Inserts the minimum number of spans needed to meet tangent or curvature requirements.

Short Edge Tolerance

In the case of cross-knot insertion, the system will not allow spans of a linear distance less than the Short Edge Tolerance.

Single Surface

This option is only available when the Span Placement option is set to One-Per-Boundary.

Turn this option on to create a single blend surface.

Turn this option off to create multiple surfaces corresponding to the boundaries between the original surfaces. This gives you much lighter blend surfaces and better continuity with the original surfaces.

Shape

Provides control over the "looseness" or "tightness" of the blend surface. If the value is greater than 1.0, the result is a blend that fits tighter to the corner of the input surfaces; if the value is less than 1.0, the result is a rounder blend that fits closer to the edges of the surface.

Explicit Control

Gives you controls of the surface degree and maximum number of spans in the new blend surface.

Explicit Control Options

These options are only available when Explicit Control is checked.

U Degree

The degree of the new blend surface. Enter a whole number from 2 to 9.

Max. Spans

The maximum number of spans in the entire blend surface, or per piece if Span Placement is set to One-Per-Boundary and Single Surface is not checked.

Flow Control

Start/Interior/End

Controls how the blend surface(s) edges (in the V direction) meet up with the edges of the boundary surfaces.

EDGE ALIGN: The tool tries to colinearly align the blend surfaces' edges or isoparms (for single surface) to the edges of the boundary surfaces in the V direction.

CONNECT ENDS: The edges of the blend surfaces meet the start and/or end points of the boundaries exactly.

DEFAULT or FREE: The edges of the blend surface(s) (in the V direction) meet the boundaries at a 90 degree angle.

Control Options

Chain Select

If this box is checked, selecting a boundary input curve also selects all other boundary curves that are tangent continuous with it.

Continuity Check

Displays a manipulator indicating continuity achieved with the existing surfaces along the blend surface edges.

Auto Recalc.

Automatically updates the blend surface as you change options. If the surface to be built is very complex and takes a long time to update, turn this option off and click the Recalc button when you want to update the surface.