Referencing Other Curve Geometry

X-Topology Surfaces are created over a network of curves. An X-Topology Curve control point can reference another curve by connecting to an individual control point, attach to a location on the curve and attach to a position on a curve defined by an intersection with a plane.

12. Create a curve with five control points shaped like the image below.

13. Create a second curve using four control points along side the previous curve like the image shown below.

14. Ensure that Object Snapping is turned On and that both Snap to Points and Snap onto Curves are on.

15. Select the second curve and using the Right-Click menu to edit the curve (Right-Click -> X-Topology Curve -> Edit) or press F2. Select and drag the top control point on the curve up to the first curve. As the control point come close to the first curve it will move onto the and the curve snap icon, (a small cross), will appear on top of the control point. The mouse cursor will display a set of links to indicate that the control point will link up to the first curve. This means that if the first curve changes shape the second curve will update to the first's geometry.

16. Let go of the mouse button and the control point is attached to the first curve.

17. Select and drag the first point. It can be moved along the curve or by dragging it away from the first curve the reference can be removed. The mouse cursor will change to a set of broken links when this is about to happen if the mouse button is release at that instant.

18. Select and drag the control point to the right end of the curve. This time a square snap icon is displayed on top of the control point to indicate that point will snap to the end point on the first curve.

Letting go of the left mouse button will create the reference.

A curve can reference internal control points of another if they lie on the curve itself. This means to reference a control point it needs to be under the influence of the Interpolate Point, Cubic Spline Curve or Knuckle Point constraints.

19. Finished editing the second curve. Select the first curve and apply a Cubic Spline Curve constraint. Select the second curve again and edit. It should be possible to reference any of the control points of the first curve.

Control points can be attached to knuckle points.

20.Finished editing the second curve, select the first and edit. Select the middle control point...

...and apply the knuckle point constraint.

21. Edit the second curve.

The control points can now be attached to the knuckle control point on the first curve.

Locating an X-Topology Curve on a Plane >>>