Recipe 5.4. Animating a 3D Shape Morph

Problem

You want to animate a 3D model morphing into a different shape.

Solution

Use the animation timelines within the Extrusion and Lathe Editors to perform "path morphs."

Discussion

Swift 3D does not support animation within the Advanced Modeler, therefore making it impossible to animate true path deformations; however, the Extrusion and Lathe Editors both contain timelines for animating "path morphs." Animating a shape change in the object's vector path creates a path morph. This process makes it possible to have an extrusion or lathe object completely change shape through relatively easy animation techniques. You can think of standard animation in Swift 3D as the motion tweening in Flash, making path morphs equivalent to shape tweening.

To perform a path morph in either editor, add a keyframe with a change to the path. The following rules restrict the types of changes that can be made:

• Although points can be repositioned freely, they cannot be added or subtracted from a single keyframe. The same number of points must remain throughout an animation. If a point is deleted from one keyframe of an animation, it will be removed from all, therefore changing the shape of the object from start to finish.

• To assist in different kinds of drawing, the editors give the option to set point types to curve, corner, or tangent. This type must not change throughout an animation.

• New path data cannot be pasted into frames in order to morph from the original shape to the new, even if the same number of points is present in each path.

Because of these restrictions, it is often easier to animate from a more complex shape to a simpler one. Keep in mind that frames can always be reversed in Flash if the opposite is required. Figure 5-28 displays a path morph applied to the previously created pawn model, which is a lathe object.

Figure 5-28. Sample frames and renders from Lathe Editor path morph