26 July 2010
When animating in Adobe Flash Professional, you can use the Motion Editor to control the shape of each property curve of a tween, except for the x, y, and z axes. By working with property curves directly, you can add complex curves to create specific tween effects. You can edit the curve of each graph with standard Bézier controls. Using these controls is similar to editing strokes with the Pen tool. Move a curve segment or control point upward to increase the property value; move it downward to decrease the value.
Control points of property curves can be either smooth points or corner points. When a property curve passes through a smooth point, it forms a smooth curve. When a property curve passes through a corner point, it forms an angle. The following depicts a property curve in the Motion Editor showing a smooth point with Bézier handles (Frame 8) and a corner point (Frame 17):
To change the shape of a curve segment between two control points, drag the segment. When you drag a curve segment, the control points at each end of the segment become selected. If the selected control points are smooth points, their Bézier handles appear.
To toggle a control point between smooth-point and corner-point modes, Alt-click (Windows) or Command-click (Mac OS) the control point.
When a control point is in smooth-point mode, its Bézier handles are exposed and the property curve passes through the point as a smooth curve.
To set the point as a smooth point, right-click (Windows) or Command-click (Mac OS) the control point and choose the Smooth Point, Smooth Right, or Smooth Left option.