What Is Twinning? When Should You Use Twinning in a Shot?

Today we're going to have a chat about twinning - what it is; what it isn't; and how to manipulate it in a character's performance! Twinning can mean a couple of different things when talking about performance animation, but in broad terms it manifests itself as one visual element appearing similar to another visual element, usually with a negative connotation.

It can take the form of:

1. A symmetrical shape made by a character when posed, or,

2. The timing of the motion used to get into a pose. It can also be both of these at the same time.

Is this confusing? Possibly, so let's imagine an example! Our hero Cedric wants to hit a striking manly pose from his normal standing-at-ease position. Bang! There it goes, and suddenly he's in a T-like pose, brandishing his muscles for all to see. That perfect T-shape has twinned the arms symmetrically through the shoulders, an example of shape twinning. Say Cedric begins and ends the movement of his arms from the one pose to another in a very similar time frame, then the human eye will pick up on the limbs seeming to move as one element and there we have temporal twinning, (that's sounds like science-fiction. Awesome).

Most of the animation theory one comes across propagates the notion that twinning stuff is always BAD, and if you have twinned actions then you will have seven years of bad luck, and shame will besmirch your good name. Why is it seen as bad? Well, it can be a holdover from people's blocking, or by paying little attention to the forces driving an action. Having Cedric hit his pose with all his twinniness(tm) going on makes him look mechanical - as if a robot control system were driving the movement rather than an organic brain operating body parts under gravity. The slower the movement, the worse twinned movements can appear, too. Yikes!

Now, the presence of twinning is not necessarily terrible, for like every animation rule or principle, it can be judiciously broken to the betterment of the performance if the animator so desires. A little sneaky study of people will show you that everyone twins gestures and poses all the time. Symmetry is a good way of adding force to an action to get a point across! What we want is to remove that feeling of Mr. Roboto whilst still retaining that sense of force, and then we're all good. How can we accomplish this? Well, let's go back to Cedric, who's still obligingly holding his Grrr pose for us.

We can prod Cedric about such that when he completes his move, he is not quite the T-shape he once was. Maybe raising one arm higher than the other would look better, which could then give us the idea of skewing his torso to one side to give us a nice little arc through the spine, reinforcing the arms and suggesting a nicer set of inbetweens. Better animation all round! Yay!As for the timing, if Cedric gets into this Grrr pose fairly quickly, then that is nice since it suggests force and strength. There are many different ways to break this up. Maybe we can anticipate one arm down before it comes up, setting the limbs a couple of frames apart? Maybe we could hit the Grrr pose at the same time but one arm could take longer to settle than the other? Maybe we can take a more flourishy arc between poses for one of the arms? Lots of options, and even the smallest little change can give the action a much more organic feel. We just have to know what to look for!

With these definitions firmly in mind, we can study a pose/action and make a few minor tweaks to better impart a sense of the organic, whilst still being mindful of the intent and force of the pose. We win!

- Guest blogger Kevan Shorey