This section of the tutorial looks at how simple constraints can be used to control the shape of curves without having to accuratly place control points in the right locations. Unlike IntelliCurves, it is not necessary to supply additional control points for the constraint tools to function. Because X-Topology curves are multi part, internal control points are generated based on the control points supplied by the user. These internal control points can be displayed from the Right-Click menu, (Right-Click -> X-Topology Curve -> Show Control Polygon).

1. Define a X-Topology Curve like the image shown below, (Create -> X-Topology Curve). The initial shape of the curve is the same as a BSpline curve and the tutorial for those curves is equally applicable to creating X-Topology Curves.

2. Curve Level constraints can be used to control the geometry for the entire length of the curve. The Polyline Constraint, (Right-Click -> X-Topology Curve -> Polyline Curve)...

...is used to change the curve into a polyline, with line segments between each control point.

3. The Cubic Spline Constraint change the curve into a BSpline curve which interpolates all of the control points. First, remove the Polyline Curve Constraint and then add the Cubic Spline Curve Constraint, (Right-Click -> X-Topology Curve -> Cubic Spline Curve).

The curve now interpolate all of the control points.