Menu : CURVE

Command: Design:Input

Shortcut : i

This command creates a curve and changes to a separate input mode where the user can interactively place points to define the shape of the curve. The command requires a curve-set to be selected as the target object. If a 3D-projection set is selected, the command will create a 3D curve, otherwise a 2D curve will be created. The functions of the input mode are discussed in detail in the Editing Functions part of this Manual.

The type of curve created is determined by variables in the Settings Window. The representation of the input curve is determined with the SettingsÞREPS mode. A linear, B-spline or Bézier curve can be created.

If the object created is linear (a polygon), the points entered are to be the vertices (corners) of the polygon.

If the object created is a B-spline, the points are taken as its control points. If SettingsÞSMOOTH is selected, the result is a smooth curve that approximates the control points. However if SettingsÞSHARP is selected, all the B-spline control points are automatically made triple so that the curve will have sharp corners just like a polygon.

If the created object is a Bézier curve, the curve will pass through the input points. In other words, the Bézier curve always interpolates the given points. If SettingsÞSMOOTH is selected the curve will be smooth. With SettingsÞSHARP, the curve will have sharp corners at the input points just like a polygon.