Modifying continuity between two chains of curves

After starting the Advanced Curve Continuity command, proceed as follows (please note that you can follow this step-by-step example by loading file: "CurveAdvancedContinuity.e3").

1	Select the chain of curves to be modified. To do this, first move the cursor onto the first curve of the chain. Then right-click and select SelectChain from This. Finally, end selection (by right-clicking and selecting Continue or by clicking on Reference curves). To change the selected chain, right-click and select Reset Current Selection. Then select another chain of curves.
2	Select the reference curves — the ones on which the target point will be chosen — using the Select Chain from This operator as you did in step 1 for the curves to be modified. To change the selected chain, right-click and select Reset Current Selection. Then select another chain of curves.
3	When you end the selection of the reference curves, a preview is displayed (if you don't explicitly end selection, the Preview ( ) button shows up on top of the selection list. Click it to get a preview of the resulting curves).The program automatically detects the two nearest endpoints of the chains and shows the solution you would get with positional continuity.   Appropriate handles are available to move both the endpoints of the contour to be modified (Fixed and Modified) and the Reference endpoint on the reference contour. Instead of using the handles, you can type the contour parameter value into the corresponding boxes. About the number of resulting curves The number of the resulting curves will be the same as the one of the curves belonging to the contour to be modified in the range between the Fixed and the Modified endpoint.   The Continuity drop-down lists enable you to select the type of continuity to be applied to the curves at the corresponding endpoint. In the case of the Fixed endpoint on the contour to be modified, the available types are the following (for a detailed description of the continuity types, see Continuity Types): Free — no continuity condition will be applied Position Tangency Curvature Torsion Smooth curvature Curvature plot curvature In the case of the Reference endpoint on the reference contour, the available continuity conditions are the same as the above ones (except Free, which is not available).
4	Now move the endpoints and set the continuity conditions as shown in the illustration below: The Weight handle and box enable you to adjust the tangency factor at the joint (supplying negative values will cause the tangent to get the opposite direction, just like double-clicking on the handle).
5	Several options are available under More Options to enable you to better control the shape of the resulting curve(s). See Additional Advanced Curve Continuity Options for details.
6	Click or to confirm your selections and create the curve(s). Click to discard your changes.

Tips and Tricks

• Additional Advanced Curve Continuity Options