SciTech

How Things Work: Clay animation

The California Raisins, Gumby, and Wallace and Gromit are all brought to life with clay. But to create a story showing these characters jumping, playing, or running, a person needs a few techniques that aren’t normally taught in high school art class.

Three-dimensional objects like clay forms or metal armature are typically animated using a process called stop-motion animation. This technique requires the forms to be filmed one frame at a time. Between each frame the animator moves the figure very slightly.

Much like flip books that, if flipped fast enough, will make the object on the page appear to move, stop motion relies on our persistence of vision. Our eyes can only process new pictures as being single entities up until a certain speed. Once the frames of a film or the pages of a flip book are changed at a rate too quickly for us to process the images as separate, we see the frames as connected.

A single stationary object, like Wallace, appears to be moving because we cannot distinguish that what we are really seeing is a series of pictures in which Wallace moves slightly each time.

Modeling clay is not the only substance used in stop motion animation. The 1933 version of King Kong also used stop motion to make a puppet wreak havoc on New York City. The two pioneers of stop-motion are Willis O’Brien and Ray Harryhausen; O’Brien is best known as the man who created King Kong in 1933, and the latter used puppets and sculptures that he created himself as the stars of his many stop-motion animations, including Clash of the Titans and Mighty Joe Young.

Most commonly, metal armature is used to support clay figures, but it is also used to support the puppets in stop-motion films. Armature serves basically as a skeleton and often includes lead wire for the movable parts (like limbs) and brass for the unmovable parts (like the chest).

One holiday favorite, Rudolph the Red-Nosed Reindeer, used metal armature inside its characters. Later, metal armature was used inside the were rabbit puppet in Wallace and Gromit in The Curse of the Were-Rabbit.

Because the Were Rabbit was covered in fur, levers had to be placed on the puppet’s back in order to make it move. Had the animators touched it, the fur might not have looked natural.

However, modeling clay does present particular challenges when animating. To create a clay animation film you need the right clay, a good set of tools, a set of figures, and sometimes sets (usually not constructed of clay). On his website, accomplished animator Vince Backeberg recommends a variety of items, like stainless steel dental tools, clay sculpting tools and hand-made tools from polypropylene plastic. Backeberg worked at Will Vinton Productions around the time the studio produced the California Raisins and the Noid from Domino’s Pizza.

The greatest challenge of working with clay, according to Backeberg, can be cleaning up after it. Clay often leaves behind “footprints,” and animators must clean up after the clay figures between shots. Because the animators must touch the clay hundreds of times for a single scene; bright colors are often avoided as they show dirt. Backeberg explained that the dull purple of the California Raisins was an ideal color to prevent marks appearing on the clay.

Clay animation also requires a camera and additional editing equipment. Camcorders can be expensive or difficult to use unless they have a single-frame shooting capacity, so amateurs sometimes use digital cameras to take single pictures, which are edited together later on a computer.
Of course, the process of moving figures ever so slightly in each frame to create stop-motion can be rather tedious, because it might take a week to make a single scene between two characters turn out as intended.

Often, animators get only one shot at “getting it right” because the process is so lengthy. However, there are many stop-motion advocates out there, and stop-motion has brought us such films as The Nightmare Before Christmas. And where would the holidays be without Rudolph and his misfit friends?