Production > Scene Planning > Animation Paths > Differences between Pegs and Animated Layers

Differences between Animated Layers and Pegs

There are two ways to create motion paths: animated drawing layers and pegs. They each have different purposes.

You can create a motion path directly on layers (animated layers).

You can control and define a trajectory using several different parameters, including:

X, Y and Z positions (3D Path or Separate Positions)
Angle (rotation)
Skew
X and Y Scales
Euler Angle or Quaternion Angle (when 3D option is enabled)
Z Scale (when 3D option is enabled)

Each parameter has its own function curve where you can add keyframes and control the easing. If you're not familiar with graphs and function curves, these are easy-to-use tools for visually controlling trajectories in the Camera and Timeline views.

By default, you can animate a drawing layer using the same parameters as a peg, but you can choose not to do so by turning off this feature. This allows you to switch your drawing layers so they can no longer be animated without a peg, which has certain advantages. In cut-out animation, it's easier to separate drawing exposure and keyframes to change the timing and rearrange keyframe position in the Timeline view. This also works for backward compatibility when bringing in templates created in older versions of Harmony so as not to lose their offset keyframes or drawing substitution keyframes.

If you do not want to animate a drawing layer, you can turn off its animation parameter. To do so, simply select the layer and in the Layer Properties view, deselect the Animate Using Animation Tools option on the Controls tab. If your layer was already animated, then your keyframes will appear dimmed so you can easily identify them as ones that cannot be modified. To modify keyframes, select the Animate Using Animation Tools options.

A Peg layer is a trajectory that contains no drawings on which you can hook your drawings.

Pegs have been used for a long time in the traditional animation process, mainly for registration purposes. Peg holes at the bottom or top of the animation paper are used to keep all the sheets even and at the same registration.

There are three peg holes in regular animation paper. The centre peg hole is round while the left and right ones are oval shaped. The oval peg holes are located on each side of the page, four inches away from the centre peg hole.

To keep the drawings together, the animator uses a peg bar. This peg bar has three pins that correspond to the shape and location of the peg holes. Peg bars are normally found at the bottom and top of animation discs.

Before digital compositing, the peg bars were also used to move layers on the camera stand to create pans and camera moves. They were the equivalent of digital trajectories. Harmony makes use of these concepts to create animation and camera motion.

A peg is composed of many customizable parameters. These parameters are:

X, Y and Z positions (3D Path or Separate Positions)
Angle (rotation)
Skew
X and Y Scales
Euler Angle or Quaternion Angle (when 3D option is enabled)
Z Scale (when 3D option is enabled)

You can control a peg’s trajectory the same way as the animated drawing layer.

A peg layer is mainly used to control a series of drawing layers, such as clouds, a school of fish or a flock of birds. You can attach them to a peg layer and make them follow a trajectory as a single unit. This makes trajectory modifications much easier and faster. When building a puppet, most of the time you will add a master peg to control your puppet as one object.

In Harmony, you can add pegs to the Node view using the Node Library view and they will instantly appear in the Timeline view. The nodes you add to the Node view are synchronized with the ones in the Timeline view.

In the Tool Properties view, the Peg Selection Mode lets you automatically select the peg layers in the Camera view instead of the drawing layers. If you animate with pegs instead of animating the drawing layers directly, enable the Peg Selection Mode to avoid having to select in the Timeline view or use the Select Parent Skipping Effects command.