Use this command to create a curve by defining a series of points through which the curve will pass. Only the points are required.

 

Optionally, you can specify the start and end tangent directions, weight, fairing technique (i.e., curve smoothing method), curve degree and choose between open or closed curves.

 

Required Inputs

 

• Points - Specify the interpolation points that the curve will pass through and middle-click to continue.

 

Optional Inputs (see below)

 

 

 

Use this command to create a curve through a series of points on a face. Both the points and the curve lie on the face.
 

Required Inputs

 

• Face - Select a face to create the curve on.

• Points - Select points on the face for the curve to pass through and middle-click to create the curve.

 

Optional Inputs (see below)

 

 

 

Use this command to create a curve that passes through a cloud of points. The required inputs include the start point and the remaining points on the curve. Optionally, you can specify the start/end tangent directions, start/end tangent weights, fairing techniques, curve degree and an open or closed curve.

 

 

Required Inputs

 

• Start - Point Select the first point on the curve.

• Points - Select the remaining points on the curve.

 

Optional Inputs (see below)

 

 

 

Start tan

Use this option to specify the tangent direction for the starting end of the curve. You can select a linear edge to define the direction or right-click for more input options.

 

Weight

Use this option to enter the start tangent weight if a start tangent direction is specified. This refers to how much influence the start tangent vector will have on the curve. In all cases, the curve will have the given tangent vectors at the ends of the curve.

 

A larger scale factor will increase the region of the curve that tends to go in the tangent direction. Extremely small scale factors can produce very tight "hooks" on the ends of the curve.

 

End tan

Use this option to specify the tangent direction for the end of the curve. Input options are similar to Start tan above.

 

Weight

Use this option to enter the end tangent weight if an end tangent direction is specified. The same conditions apply as the Start tan Weight above.

 

Fairing

Use this option to select a fairing technique. Curve fairing refers to the process of shape editing to remove unwanted imperfections in a curve. The types of imperfections that fairing will remove include:
 

• Ogee - Inflection point (sudden 180 degree change in curvature).

• Flat spot - A local minimum of curvature.

• Buckle/bump - A local maximum of curvature.

• Bulge/knob - A discontinuous curvature.

• Crease - A discontinuous tangent.

 

Select from the following fairing modes:

 

• None - No fairing is applied.

• Energy - The curve is created for minimum energy. This produces a less stressful and a more gradual smoothing of the curve.

• Variation - The curve is created with less curvature variation such as with lines and circular arcs.

• Jerk - The derivative of the curvature is minimized. A curve with less total fluctuation is created.

• Bending - An approximated form of the Energy method that requires less calculation time is used.

• Tension - Uses the same techniques as the Energy method and couples it with the desire to produce the shortest total curve length.

 

There is some interaction between this option and the start/end tangent weights (see above). When fairing is applied, there may be little change in the curve by modifying the tangent weight. Usually, different tangent weights will produce different curves even when fairing is active. It is only for extremely simple curves that fairing might always produce the same curve despite initial tangent weight values.
 

Use the Draw Curvature Plot of Curve command to graphically display and compare the results of these curve fairing methods.

 

Degree

Use this option to specify the degree of the resulting curve. This refers to the degree of the equation that defines the curve. Curves of a lesser degree are less exact and require less storage and computation time.

 

Curves of a higher degree are more exact and require increased storage and computation time. Select from Degree 1 - Degree 6.

 

Create curve open

Check this box if you want an open curve.