About Creating Surfaces from Curves

The surface creation with OmniSurf includes four basic surface types: Flange, Blend, Sweep, and Loft from which different variants can be created depending on the support geometry.

Flange

Flange surfaces are created from a curve (Curve) or a edge (Surface Curve) used as guide curve (Rail). Length and Angle define extent and direction of the flange surface. The basic flange direction is the direction with a flange angle = 0 deg.

The order of the flange surface in direction of the guide curve is adopted from the guide. The order perpendicular to the guide is always 2.

Blend

Blend surfaces are created between two or multiple parallel curves or surface edges. In case of surfaces edges, the blend surface is connected along the edges with the selected continuity.

Sweep

A swept surface is created by dragging one or several profile curves (Gen) along a guiding Rail curve. In case of surfaces edges, the swept surface is connected along the edges with the selected continuity.

The curves or surface edges may be perpendicular or form a H, L, T, U, or X shape.

The result depends from the number and topology of the input curves, and the selection order.

The selection order determines which curves are defined as Rail and Gen.

If multiple solutions are possible, a list is available in the panel to choose the desired solution. In the work area, the input curves which are used for the surface creation are highlighted.

The options offered in the panel depend on the selection. If, for example, no continuity modification is possible, the continuity options are not available.

Important: The default topology tolerance set in Me > Preferences may influence the selector decision which surface type is created. This may lead to an unexpected result. If, for example, the distance between two perpendicular curves or surface edges is outside the topology tolerance, a Parallel Curves surface type is created instead of a Perpendicular Curves surface type. For more information, see Customizing Preferences.

Loft

A lofted surface is created through multiple Gen curves (Perpendicular Curves N) and two or multiple Rail curves (Curve Net) in both U and V direction.

Note: The selection order is decisive for the surface type detection: Select first all guide curves and then the profile curves.

The following overview shows the different surface types with their required input geometry:

Surface	Surf Type		Required Input
Flange	Curve		Curve
	Surface Curve		Surface edge
Blend	Parallel Curves		2 parallel curves
	Parallel Curves N		At least 3 parallel curves
Sweep	Perpendicular Curves (2)		2 perpendicular curves
	Perpendicular Curves (3)		3 perpendicular curves
	Perpendicular Curves (4)		4 perpendicular curves
Loft	Perpendicular Curves (N)		n perpendicular curves
	Curve Net		Curve net