B-Spline Surface

A parametric surface (also known as a NURBS surface) that is commonly used in geometric modeling. It accommodates a wide variety of shapes and conveniently exchanges geometry between applications. See Surface.

Boundary Curve

A curve that defines the outer boundary of a Style surface.

Boundary Surface

A surface that has a rectangular or triangular boundary. The complete boundary of the surface is defined by a set of primary curves with optional internal curves.

Close Point

The point at which a closed curve starts and ends.

Child

Any entity that references another entity. For example, a surface is a child of the boundary curves that were used to create it. See Parent.

Composite Surface

A surface that is built with a composite chain as a single boundary or internal curve. In Style, a composite surface is composed of a set of surfaces but is treated as a single entity. Outside Style such surfaces are treated as a single quilt.

Connection

Specifies how a smooth join between two curves or surfaces is to be computed.

Continuity Level

A description of the connection between two curves or along the shared boundary between two surfaces. G-3 - Acceleration-continuous connections have smooth curvature continuity. G-2 - Curvature-continuous connections have the same curvature at each point along the boundary. G-1 - Tangent-continuous connections have the same tangent at every point along the boundary. G-0 - Position-continuous connections have only the shared boundary, but not shared tangents or curvature.

Control Mesh

The control points for a surface are called the Control Mesh.

Control Points

Control points display the underlying B-Spline mathematics of a curve or surface. Control points do not necessarily lie on the curve or surface.

Control Polygon

The control points for a curve are called the Control Polygon.

Convert

The Convert command changes the type of the curve. For example, using the Convert command, you can change a planar curve to a free curve.

COS

See Curve on Surface.

Curvature

How much a curve or surface bends at any given point. A straight line has zero curvature.

Curvature Continuous

See Continuity Level.

Curvature Plot

A graphical representation that shows the curvature at a set of points along a curve. Curvature plots are used to analyze the smoothness of a curve.

Curve

A smooth path in space which is defined by two or more points.

Curve from Surface

A free, COS, or isoline curve that is created from an isoparametric line of a surface.

Curve on Surface

A curve that lies on one or more surfaces.

Drag (cursor)

To press and hold the mouse button while you move the mouse to a new position.

Endpoint

A point at the end of a curve.

Fixed Point

One of the points used to define a curve. Fixed points always lie on a curve.

Follower Connection

A type of connection in which the follower surface assumes the direction of its leader surface along the shared boundary. The leader surface does not change. See Connection.

G0, G1, G2, G3

Mathematical terms for continuity levels. G0 is position continuous. G1 is tangent continuous. G2 is curvature continuous. G3 is acceleration continuous. See Continuity Level.

Grid

A pattern on or referencing the active datum plane of equally spaced horizontal and vertical lines that can be used as a guide during feature creation.

Internal Curve

A curve that defines the shape of a surface, but is not one of the boundary curves.

Internal Point

One of the defining points of a curve that is not an endpoint.

Knots

Parameter values at which the underlying surface patches join together to form the full surface. The locations of the knots in the parameter space work together with the positions of the control points in the model space to completely define the shape of the surface. For Style curves and surfaces, the number of control points in a given direction is always four greater than the number of knots in that direction for a particular curve or surface.

Leader Connection

A type of connection in which the leader surface governs the direction of its follower surface along the shared boundary. See Connection.

Linked Object

An object with one or more parents that will change if the parent object is changed. In some cases, objects can be unlinked to remove the dependency on the original geometry. See Local History, Child, and Parent.

Local History

A mechanism for remembering how the individual entities in the Style feature were constructed, so that any changes to geometry are propagated throughout the feature. See Parent, Child, and Regenerate.

Loft Surface

A surface that is created from a set of non-intersecting curves.

Mesh

Lines that approximate the contours of the surface. Also called flow lines or parametric lines.

Natural Tangent

The tangent at the endpoint of a curve that is computed when no fixed tangent is specified. To ensure a relaxed curve shape, a natural tangent is recomputed whenever the curve changes shape.

Normal

A vector that is perpendicular to a curve or surface or datum at a given point.

Nudge

A small, incremental adjustment to a point location.

NURBS

See B-Spline Surface.

Orthographic Views

The plan, side and rear views.

Parent

An entity that is used to define another entity. For example, the boundary curves that are used to create a surface are its parents. Several parents can make an entity. See Child.

Planar Curve

A curve in which every point on the curve lies on a particular plane.

Point

A position in space that is defined by x-, y-, and z-coordinate values.

Preference

Settings that determine user choices for items such as display and point creation. Preferences are remembered throughout a session and can be restored in later sessions if required.

Proportional Copy

Copy of a curve that retains the proportions of the original curve, when the endpoints are moved to a new position of the first curve in the selected geometry are moved to new positions during duplication.

Radial-Path Planar Curve

A curve that lies on a soft-plane that it is normal to the parent curve at a selected point on the parent curve.

Regenerate

The process of recomputing child geometry when parent geometry has changed. For example, if a boundary curve is changed, the regeneration process would recompute the surface. See Local History.

Resolve

If geometry fails to regenerate, you can resolve the failure by choosing one of the resolve actions.

Snapping

An option that directs the cursor to gravitate to points, curves, edges, and surfaces.

Soft-plane

A plane that references Style curves. During curve edits, the soft-plane can slide along its parent curve while remaining normal to the parent curve at all times. When the parent curves are updated, the planes and the planar curves are regenerated.

Soft Point

A point that references Style curves, datum curves, edges, and surfaces, and can slide along the reference curve during curve edits.

Soft points are created by snapping to existing reference geometry. To enable snapping, click Style > Operations > Snap, or hold down the SHIFT key while you move the soft point on the screen by dragging it. The cursor is followed by a snapping cursor (a cross-hair) when snapping capability is enabled.

Surface

An association of four intersecting curves that make an enclosed area. A surface is a mathematical transformation that maps a simple, flat area into a 3D continuous area in model space. See B-Spline Surface.

Suspend

You can Suspend child geometry. Suspension causes the child to fail during regeneration. You will have to resolve the failure to regenerate. See Regenerate and Resolve.

Sweep Surface

A surface that is created from one or two primary curves and at least one additional curve that intersects the primary curve or curves.

Tangent

The direction of a curve at a particular point.

Tangent Continuous

See Continuity Level

Unlink

The Unlink command removes all optional references. For example, for surfaces, the internal curves are optional. Using the Unlink command, you can remove the internal curves from the surface without affecting the surface.

View

The multiple view environment in Style allows for the creation of curves in either two dimensions and specifying the third dimension after the 2D shape or in 3D.