Fix Points

Fix points on a curve are used to modify interpolation splines. Fix points define the area of change on the curve. If two fix points are set on a curve, the curve can be modified only between these two fix points. The
Tangential or curvature continuous condition (tangential or curvature continuous) of the curve on either side of the fix points remains unchanged. Fix points are represented in orange. Note that orange is the default color; you may change it by “Color Switches”.

• When you move a fixed point it becomes unfixed unless it is also an end point. End points remain fixed.

• A fixed point always has a curvature continuous condition, but it can be made tangential by clicking ChangeTan. When an end point, which is a fixed point, is moved, it has a tangential condition.

• If you set an EndCondition and another curve is appended at this interpolation point, the previous end point becomes a fix point. If there was no special end condition set, then no fix point is set at the previous end point.