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 two types of deformers available in Harmony Advanced:

Bone
Game Bone

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 a Bias property. The articulation folds also look slightly more rounded.

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 layers. 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.

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.

How to create a Bone deformer

Once your element is selected, select the Rigging tool in the Deformation toolbar.

In the Tool Properties view, enable the Bone mode.

Click where you want to create the root articulation of the bone structure. The root articulation should be the one that is bound to the remainder of the body. For example, for an arm, the root articulation would be its shoulder.

Click where you want the second articulation to be created.

A bone will be created between the first and second articulation.

Click where you want the next articulation to be created.

Observe that, as you create a new point, the previous point now has a circle around it. This is the radius of the articulation, which allows you to determine how much of the drawing should be part of the articulation. Every point in a bone deformer, except for the first and the last one, has a radius.

Click and hold the previous articulation's radius control point and adjust the articulation's radius so that it properly covers the articulation.

Repeat this until you are finished creating the Bone chain. Make sure you build each articulation in the right order going from the root to the extremity.

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.

How to animate Bone and Game Bone deformations

In the Timeline view, collapse your character using the Expand/Collapse arrow.

Collapse Layers

Select the first frame of the scene.

Select First KeyFrame

To ensure your model doesn't disappear after 1 frame, open the Extend Exposure dialog by doing one of the following:

Right-click on the first frame in the Timeline and select Extend Exposure.

Press F5.

In the Extend Exposure dialog, type in the amount of frames in your scene and confirm. This will make your model exposed (visible) throughout your whole scene.

Now, we will make your character's first pose. First, make sure there is a keyframe on the first frame of every layer of the model. This ensures that when you make the second pose later, your first pose will not be affected. To do this do one of the following:
- In the Timeline toolbar, click the Add Keyframe button.
- Right-click and select Add Keyframe.
- Press F6.

A keyframe is added on the current frame.

Select First KeyFrame

In the Tools toolbar, select the Transform tool or press Shift + T.

In the Tools toolbar, if Animate Off or Animate Onion Skin Range mode is selected, click on it to open the Animate pop-up menu and select Animate Current Frame.

Do one of the following:

In the Camera or Timeline view, select one of the drawing layers linked to the deformation chain you want to animate.
In the Timeline view, select any part of the deformation chain you want to animate.

In the Deformation toolbar, either:
- Click the Show the Selected Deformation Chain and Hide All Others button to show the selected element's deformation chain and hide any other deformation chain that is currently displayed.
- Click the Show Selected Deformers button to show the selected element's deformation chain along with any other deformation chain that is currently displayed.

The selected deformation controls appear in the Camera view.

In the Camera view, do the following:

To rotate the whole limb, click and drag on the first bone. This will rotate the first bone and all subsequent bones.

To bend the limb, click and drag on another bone. This will rotate the bone and all subsequent bones, but will leave the bones before it in their current position.

To reposition an articulation, click and drag on its control point. This can be used to rotate, shorten or extend the bone, and will offset all subsequent bones.

To shorten or extend a bone without rotating it, press and hold the Alt key, then click and drag on its control point.

To offset the whole limb, click and drag on its root point.

TIP You can also nudge an articulation in any direction by selecting it, then pressing on the arrow keys.

In the Timeline view, go to the frame on which you want to set the next key pose.

Add a keyframe on the current frame by doing one of the following:

In the Timeline toolbar, click the Add Keyframe button.

Right-click and select Add Keyframe.

Press F6.

Transform your deformer's points to make your new key pose.

Repeat the previous steps until your animation is complete.