3D Curves overview

The ability to create and modify curves in three-dimensional space is a fundamental change to the way in which surfaces can be defined in Creo Elements/Direct Modeling.

The 3D Curve functions help you create and modify 3D curves using a variety of direct and indirect methods. The 3D curves are incorporated into a wire part. The curve elements are straight lines, arcs, circles, spline curves, spirals, and curves on surfaces. These 3D methods differ from the methods used to create 2D curves because workplanes are not required, but you can use them as guides.

The 3D curves you create can be applied to many other Creo Elements/Direct Modeling functions, particularly those involving the creation of surfaces. These 3D curve functions can help

• Improve the surface Skin operation by constructing a surface mesh from 3D spline curves.

• Simplify operations which previously required you to create and align multiple workplanes.

• Better control the definition of surfaces by using elements of analytic 3D geometry such as straight lines or arcs to define vertices at various points on a surface.

• Enhanced creation of spine elements for the freeform sweep operation by connecting a series of 3D curves. This is particularly useful when adding cable or pipe elements to a model.

Create a 3D curve using existing geometry

The 3D Curve menu provides indirect methods which help you create 3D curves from edges or faces that are part of an existing solid. For example, you might use the Convert function to select a set of edges on an existing part, convert each edge to a spline curve, and then combine these spline curves into a wire part.

You can select the desired geometry and, depending on the method chosen, Creo Elements/Direct Modeling creates 3D analytical curves or 3D spline curves from that geometry. The curves resulting from these operations are incorporated into wire parts.