# Create curves from other objects

Use existing objects to create curves by using the objects as location references or by copying borders, edges, and outlines.

## Draw a curve through points

Create a curve from polyline vertices.

Fit a curve through point objects.

Fit curves through surface control points.

## Blend between two curves or surfaces

Create an arc blend curve between two curves.

Connect two curves maintaining continuity.

Connect two curves with continuity control.

Create a line segment between two curves and trims or extends the curves to meet it.

Add an arc between two curves and trims or extends the curves to the arc.

## Duplicate surface edges

Create a curve or polyline that copies a surface, polysurface, or mesh border.

Create a curve that copies a surface edge.

Create a curve that copies a polysurface face border.

Creates a polyline that duplicates the edge of a mesh.

Create a polyline that duplicates the boundary of a mesh hole.

## Contour and section

Create a spaced series of planar curves and points through objects.

Create cross-section curves through profile curves.

Create a polyline outline of mesh objects or surface render mesh.

Create a planar curve by intersecting a plane with points or pointcloud objects.

Create a planar curve or points from the intersection of a cutting plane through objects.

Create outline curves from a surface or polysurface.

## Create curves from other curves

Create a curve by averaging two input curves that are planar in two different views.

Copy a curve parallel to the original.

Copy a curve on a surface parallel to the original.

Copy a curve on a surface parallel to the original in the surface normal direction.

Project curves/points toward a construction plane to intersect a surface.

Pull curves/points in the surface normal direction to intersect a surface.

Create the shortest possible curve (geodesic) between two points on a surface.

## Create curves from surfaces

Shoot a ray at a collection of surfaces to create a polyline path.

Project a surface boundary and trim curves onto the world xy plane.

Create point objects or curves at the intersections of curves and surfaces.

Find the intersection of one set of objects with another set of objects.

Project geometry to the construction plane.

## See also

Draw lines and curves

Edit curves

Extract object sub-elements

Rhino for Mac © 2010-2017 Robert McNeel & Associates. 24-Oct-2017