How to Use Deformers

Deformers give the ability to animate objects and parts of a character model using computer generated deformations. Deformations work by creating control points on a drawing and, when you move those points, the drawing is bent or distorted so that the parts of a drawing that are bound to a control point follow that control point wherever you position it.

Deformers can substantially increase the range of movements and animations a cut-out character rig is able to perform without having to draw new poses for it or resorting to frame-by-frame animation. A cut-out character rigged with deformations can be animated in a way that likens the fluidity and flexibility of traditional animation. Additionally, deformers can be used to tweak, enhance or facilitate frame by frame animation when needed.

Deformers work by rigging them on the body part you wish to deform, building the deformation structure, then animating it. This can be done easily using the Rigging tool.

There are five types of deformers available in Harmony Premium:

  • Bone
  • Game Bone
  • Curve
  • Envelope
  • Free Form

Bone Deformer

The Bone deformation allows you to create a bone-like structure in which each part is solid, but with articulations that are flexible. This is mostly useful for animating a character's limbs, such as the arms or legs, or other parts that can be articulated such as torsos or fingers.

For example, a Bone deformation can be used to articulate an arm that is made of a single drawing, so that the upper arm and forearm can be moved independently, without having to draw the upper arm and the forearm on different layers. Harmony will deform the drawing to make it look articulated. The different parts of a Bone deformation can be rotated around their joint, extended and shortened, giving you the same capabilities as animating articulations on different layers, without having to worry about parts detaching, pivot points, or clipping outlines.

Game Bone Deformer

The Game Bone deformation is very similar to the Bone deformation. It allows you to create structured comprised of points, which represent the articulations, and straight line segments linking those points together, representing the bones. The Game Bone deformation is different in that it is optimized to be exported to game engines such as Unity. Hence, it is usually only used to animated characters destined to be imported to Unity games, rather than for animation productions.

Contrary to the Bone deformations, Game Bone deformations do not have Bias and Region of Influence properties. The articulation folds also look slightly more rounded.

Curve Deformer

The Curve deformation allows you to deform parts of a character using a Bezier curve. It is different from the Bone deformation in that the lines connecting the points are curvilinear. Hence, Curve deformations are typically used to deform parts of a character that are flexible, such as hair, mouths, eyebrows, or torsos. They can also be useful to animate limbs in a rubber hose style, where arms and legs are animated like extensible, flexible tubes rather than articulated bone structures.

By manipulating the curve's points and their Bezier handles, you can change the curve's direction, shape and length. A drawing rigged with a curve deformation does not merely bend, it will deform along its entire length to match the curve deformation's shape.

Envelope Deformer

The Envelope deformation allows you to create an envelope around a drawing, then deform the entire drawing by manipulating the envelope's points and curves. They can be used to deform parts of a character with a fluid shape, such as hair, cloaks, shoulders, chins and so on. Envelope deformations can also be used to deform rigid parts of a characters so as to make them look like they are seen from different angles. This is commonly done to make character rigs rotate without swapping drawings, and using this technique makes it possible to animate a character rig going from one angle to another without having to swap drawings or character models.

Envelope deformations are very similar to Curve deformations, except that their last point connects to their first point to make a closed shape. Also, contrary to Curve deformations, all points move independently from one another, whereas the first point of a Curve deformation offsets all its other points.

Free Form Deformer

The Free Form deformation allows you to deform drawings by creating points anywhere, either on their contour or inside their surface, and moving them around freely. It works a bit like laying down a piece of cloth with a pattern on a surface, then pulling on parts of this cloth to warp its shape and its pattern.

The Free Form deformation's main purpose is to deform textured shapes and complex drawings. Contrary to the Envelope deformation, which merely bends the contours of a drawing without deforming the texture inside it, the Free Form deformation stretches and squashes all the artwork between its control points. Moreover, since the Free Form deformation allows you to create points anywhere on a drawing, including inside its contour, you can actually control precisely how the texture is deformed.

Creating Deformers

The most simple way of creating deformers is to use the Rigging tool, available in the Deformation toolbar. With this tool, all you need to do to create a deformer is to select the layer you wish to deform, then place each point of your deformer in the Camera view.

Deformers exist in your scene as a hierarchy of deformation nodes. When you create a new deformer, the first point you set is the deformer's root, and each new point you create is a child of the previous point. Deformers are hence created in a chain, and should be created with your character's hierarchy in mind. For example, when you create a deformer for an arm, the root should be the shoulder joint, the second point should be the elbow and the third should be the wrist.


Since every deformation point is a separate node, creating long deformation chains is likely to add bulk to the Timeline and Node views. It is recommended to make sure that the Automatically create a group when creating a new deformation rig option is enabled in the Tool Properties view before building a deformer. This option is enabled by default. When enabled, deformation nodes that are part of the same chain are automatically grouped together.

A deformer affects all the layers under its hierarchy. When you create a new deformer using the rigging tool, it is automatically created as a parent of the selected layer, and will affect the selected layer and all its children. Hence, it's important to select the right layer before attempting to create a deformer.

For example, if you wish to create a deformer for an arm, and the arm is broken into several layers, you could rig the arm in a hierarchy where the upper arm is the root, the forearm is the upper arm's child and the hand is the forearm's child. Then, if you create your deformer on the upper arm, it will be created as a parent of the upper arm, and will hence affect the whole arm.

You can also group several layers under a peg, and create your deformer with this peg selected. When you create a deformer on a peg, the deformer is created as a child of the peg, but as a parent of all of this peg's children. This is because a peg is likely to be more useful over a deformer than under. If you move layers that are under a deformer, they will exit the intended deformation zone, and may appear severely warped and distorted. Hence, it's better to create deformations under pegs as much as possible, and pegs under deformers should only be animated if the deformer is left untouched. Since the deformer will be created as a parent of all the peg's children, it will affect all the layers under the peg.

Displaying Deformers

Harmony lets you control which deformers are displayed in the Camera view independently from the current selection. When you create a deformation chain, its deformation controls are displayed in the Camera view. However, if you select an existing deformer or a layer that's connected to existing deformers, its deformation controls won't display automatically. Likewise, deselecting a deformation chain will not hide its deformation controls.

Before you can animate or modify an existing deformation chain, you must manually display it.

Animating With Deformers

Just like with animating pegs and drawing layers, you can animate your deformers by creating keyframes on their corresponding layers in the Timeline. Animating deformers works exactly like making modifications to a deformer, except it requires using the Transform tool instead of the Rigging tool. When the Transform tool is selected, deformation controls in the Camera view display in green, which means they are in animation mode, whereas when the Rigging tool is selected, they display in red, meaning they are in rigging mode.