Secondary Animation

Another term for secondary animation is ‘follow through’ animation (Hogue par.1) (Lightfoot par.6). This principle of animation concerns the secondary movement that follows after the primary movement. This is so that animation can be believable despite involving movements of a subject that are exaggerated and impossible within real life. ‘Secondary’ or ‘follow through’ animation therefore allows the animator to make the audience believe that what they are viewing is real. Examples are, clothing, hair, extremities or any other object that is connected to another object that dictates its movement. Even though secondary animation is not distinctly noticeable, it compliments the whole animation.

According to Ollie Johnson and Frank Thomas who were Disney animators, “DRAG," in animation, for example, would be when Goofy starts to run, but his head, ears, upper body, and clothes do not keep up with his legs (Lightfoot par.6). They state ‘Drag’ as example of how secondary animation is an important aspect of their animations created within the Disney studio.

Hogue describes secondary animation further according to Newton’s first law of motion, “Objects in motion tend to stay in motion, and objects at rest tend to stay at rest unless an outside force acts upon them” (par.2). If one understands how objects move within reality, even a basic understanding of physics, they will have more capability to create believable animation. He also mentions that secondary animation is, “Slightly delayed due to the natural laws of physics and gravity” (par 1). Understanding gravity and the laws of physics will allow the movement to be resemble movement within the viewers reality allowing them to believe what they are viewing is a reality.

Jones explains the aspects of secondary animation in detail:

Follow Through depends on:
• Primary action of the character
• Weight and degree of flexibility of appendage
• Air resistance• Follow Through is how you terminate the motion (par. 7)

Not only does the speed, direction and weight of the primary motion effect the secondary motion but the environment it is situated within does as well.

Overlap depends on:
• Force transmitted through a flexible joint
• Progressively Breaking Joints
• No complete stop, before another action is started
• Nothing happens at the same time, this will give a feeling of solidity and weight (Jones par.7)

By placing the begging and end of secondary animation on separate keys than the primary animation, the animation as a whole will be more believable because secondary movement in reality. Also, because it ends after the end of the primary movement it continues despite if the primary object has stopped dead. According to Ollie Johnson and Frank Thomas, “Overlapping action is when the character changes direction while his clothes or hair continues forward” (Lightfoot par. 6). The animation not only is more believable but more visually stimulating because of the extra movement.

Follow Through: Posing Overshoot

Posing Overshoot:
• Natural motion does not stop abruptly or it will look mechanical
• Organic motion moves a little past the termination point before the “settle” pose…this is called “overshoot”
• Like a pendulum swing, the joints will over compensate for the motion and settle; then come to a complete rest
• Overshoot and Settle add accent and weight to your moves
• General Rule: 6-8 frames to settle, and at least 8 frames for the overshoot. If its only a hand gesture use less time (Jones par.10)

Here Jones explains where to situate the keys of the secondary movement on the timeframe. ‘Settle’ is the end of the secondary animation situated after the primary motion.

Overlapping Motion: Progressively Breaking Joints

Using Timing for Overlap:
• Each part of the hierarchy must stop at a different time to achieve overlapping motion = Progressively Breaking Joints
• The “lag” in timing of each joint in the hierarchy creates a whipping motion
• The breaking of each joint works well for cloth or appendages that are light enough to demand the fluid action
• The end of the tree is the last thing to come to rest and usually moves more than the rest of the tree
• Can help eliminate twinning, through delayed parts (Jones par. 12)

The object that is secondary in motion to the primary object will more than likely be long and flexible. Therefore movement will start from the beginning to end of the object, with more motion towards the end of it like a whip. Extremities such as the hand and head may require such secondary animation. The following part of the object will overlap the previous part. For example, the movement of the head will overlap movement of the neck or movement of the hand will overlap movement of the forearm.

In conclusion, there are many elements within secondary animation. ‘Drag’ where the movement of secondary objects are determined by the movement of the primary object. ‘Overlap’, when the motion of the secondary object ends or ‘settles’ after the end of the motion of the primary object. In addition, not only does the aspects of the primary object such as its speed, direction and weight determine the motion of the secondary object. The environment does as well such as its weather conditions and physics. Secondary animation not only compliments the primary motion of objects by allowing them to be more believable but also makes the animation more visually stimulating as a whole.


Works Cited:

Hogue, Mike. “The Importance of Secondary Animation”. G4 Tech Tv. 2006. <http://www.g4techtv.ca/callforhelp/shownotes/0420.shtml?regular> [accessed 01 May 2008]

Jones, Angie. “Traditional Principles Applied to CG”. Scratch Post Artist Resource. July 2001. <http://www.thescratchpost.com/features/july01/features1d.shtml> [accessed 03 May 2008]

Lightfoot, Nataha. “Principles of Physical Animation”. FrankAnOllie. 2002. http://frankanollie.com/PhysicalAnimation.html [accessed 03 May 2008]