Coons

Creates a surface blended between four boundary curves.

Curves must intersect as in the first of the pictures below. In order to be precise in placing the points, it is recommended to enable snap to grid when using this modeling tool.

The Coons modeling tool takes its name after the developer of this surfacing technique, S.A. Coons.

How to use

1. Click the Coons icon or choose the Tools > Surfaces > Coons command.

2. The program console prompts Pick curve #1.

3. Pick the first curve that will be used as a boundary of the Coons surface. Once picked, the curve turns green.

4. The program console prompts Pick curve #2.

5. Pick the second curve making sure that it is consecutive to the first one, i.e. the first point of the second curve should coincide with the last point of the first curve.

6. At the program console prompts Pick curve #3 and Pick curve #4, pick the two curves.

Note: The Construction Tree allows you to modify any boundary curve only if intersections between curves are respected. If you move the middle points of a curve, the Coons surface will automatically be updated.

If you move the start/end point of a boundary curve you will have to adjust the end/start points respectively of the other curve, in order to restore intersections. The four boundary curves should always determine an enclosed region.

Options

Curve #1

Curve #2

Curve #3

Curve #4

To replace a boundary curve.

Views / Modeling Tool panel. Switch the Replace check button on and pick another curve in the scene. The Coons surface will automatically be updated if start and end points of the new curve intersect with the other boundary curves thus determining an enclosed region.

Type of interpolation

To set the type of interpolation to be used to generate the Coons surface.

Modeling Tool panel. Switch the chosen radio button on. You have two options: Bilinear and Bicubic.