coons

Creates a coons patch through a selected loop of 2, 3 or 4 curves.

Inline mode usage

coons -h
Displays the help file that summarizes the parameters for this command.
coons –s all
Selects all curves of the scene.
coons –s <name>
Selects <name> curve.

Interactive mode usage

Invocation
coons
Parameters
  • Two, three or four curves used for the creation of the coons patch. The set of selected curves must form a closed loop.

Example:

We are going to create a coons patch from a set of four curves, so the first step is to create the curves. For this, we will use the curveInterpolation command:

>curveInterpolation
Degree [3] 3
Select curve points [Press Enter when done]
Point 0 [x y z] 0 0 0
Point 1 [x y z] 1 0 2
Point 2 [x y z] 2 0 1
Point 3 [x y z] 4 0 0
Point 4 [x y z]:
>curveInterpolation
Degree [3] 3
Select curve points [Press Enter when done]
Point 0 [x y z] 4 0 0
Point 1 [x y z] 4 1 0.5
Point 2 [x y z] 4 3 1
Point 3 [x y z] 4 4 0
Point 4 [x y z]:
>curveInterpolation
Degree [3] 3
Select curve points [Press Enter when done]
Point 0 [x y z] 4 4 0
Point 1 [x y z] 3 4 0.5
Point 2 [x y z] 1 4 0
Point 3 [x y z] 0 4 2
Point 4 [x y z]:
>curveInterpolation
Degree [3] 3
Select curve points [Press Enter when done]
Point 0 [x y z] 0 4 2
Point 1 [x y z] 0 2 1
Point 2 [x y z] 0 1 0.25
Point 3 [x y z] 0 0 0
Point 4 [x y z]:

Remember that you need to press Enter when all the points of a curve have been introduced. The result of these curves are shown in the following figure:



Figure 1. Curves used for the coons patch

Now we are going to create the coons surface. To do this, use the coons command:

>coons
Select a closed set of 2, 3 or 4 curves (press Enter when done) 
>

The result is shown in the following figure:



Figure 2. Resulting coons patch