Creating Bone Tool For Stroke Animation: A Step-By-Step Guide

The Bone Tool is a kinetics motion mechanic in Adobe Animate CC that helps add structure to an object or symbol. It is a useful tool for animators who want to make objects move fluently without having to rely on frame-by-frame placements or translating an idle character. The Bone Tool is used to construct a digital skeleton for an object, allowing for more fluid and detailed movements. It is important to place the joints correctly to achieve precise movements and avoid clipping. The Bone Tool is flexible and can be used to create a range of movements, from simple waves to more complex animations. It is a powerful tool that can bring life and depth to 2D characters and creatures.

Locate the Bone Tool in the toolbox tab in Adobe Animate CC

To locate the Bone Tool in the toolbox tab in Adobe Animate CC, open the toolbox menu by going to Window > Toolbox and clicking on the bone icon. This tool is a kinetics motion mechanic used to add more definite structure to an object or symbol. It is used to create and manipulate armatures, the skeletal structures that underpin the movements of characters in 2D animation.

By connecting symbol instances (representations of individual body parts) with bones, animators can control the movement of each body part relative to its connected counterparts. This enables fluid and realistic character animations, mimicking the natural movement of the human body.

The Bone Tool can be used to create an armature by defining the root bone, the starting point of the armature, and attaching subsequent bones to it. First, select the root bone by clicking on the symbol instance you want to serve as the root bone. The bone will automatically connect to the symbol where you click. Then, while holding down the mouse button, drag the Bone Tool to another symbol instance and release it to create a new bone connecting the two symbol instances. Repeat this process to add more bones to the armature.

Once you've created your armature, you can modify the placement and orientation of the bones and symbol instances to refine your animation.

Understand the basics of animation strategies

Animation is a complex art, and there are many strategies and principles to consider when creating a believable, engaging animation. Here are some of the basics to help you understand the fundamentals of animation strategies:

Inverse Kinematics (IK)

Inverse Kinematics is a strategy that uses bones chained into linear or branched armatures to animate objects. IK allows for natural, fluid motion by specifying the start and end positions of bones on a timeline. This technique is ideal for creating realistic, weighty movements, especially when combined with the Bone Tool.

Bone Tool

The Bone Tool is a kinetics motion mechanic that adds structure to an object or symbol. It essentially constructs a digital skeleton for your object, allowing for more precise and detailed movements. When using the Bone Tool, it's important to place the joints accurately to achieve the desired movement without any clipping or jarring poses that could break the immersion of your animation.

12 Principles of Animation

The 12 Principles of Animation, introduced by Disney animators in 1981, provide a comprehensive guide for creating realistic and engaging animations. While some principles may be more relevant to traditional hand-drawn animation, many still apply to modern computer animation. Here are some of the key principles:

• Squash and Stretch: This principle gives a sense of weight and flexibility to objects or characters. It involves distorting objects, like squashing a ball when it hits the ground, to create the illusion of outside forces acting on it.
• Anticipation: This technique prepares the audience for an action, making it more realistic. For example, a golfer swings their club back before hitting the ball.
• Straight Ahead Action and Pose to Pose: These are two different approaches to drawing. Straight Ahead Action involves animating each frame sequentially, creating fluid movement but making it challenging to maintain proportions. Pose to Pose starts with keyframes and fills in the intervals, making it easier to maintain proportions and focus on composition.
• Follow Through and Overlapping Action: These principles make movement more realistic by ensuring that different parts of an object or character continue moving at different rates after the main action has stopped, mimicking real-world physics.
• Ease In, Ease Out (Slow In and Slow Out): Objects in the real world need time to accelerate and decelerate. This principle adds more frames at the beginning and end of an action sequence to create a slow in and slow out effect, making movements more realistic.
• Timing and Spacing: The number of frames between poses and their placement affect the speed of action and can be used to establish mood, emotion, and personality.
• Exaggeration: Exaggeration adds appeal and emphasis to movements. It can be used to create comical effects or enhance the readability of actions while still maintaining a connection to reality.

These are just a few of the basic animation strategies and principles to consider when creating an animation. Mastering these fundamentals will provide a strong foundation for your future projects.

Draw your object

The object, also known as the symbol, is the fundamental component of the animation you want to create. You can draw anything, from a simple stick figure to a complex character, depending on your skill level and the amount of time you want to spend on this project.

If you are a beginner, it is recommended to start with a basic design and keep your object simple. You don't need to be a proficient artist to animate well, but it certainly helps to have some drawing skills to create appealing visuals.

• Use a drawing tablet or electronic drawing device. Using a mouse can be strenuous and overwhelming.
• Start with basic shapes. Draw circles, rectangles, and triangles to create the foundation of your object.
• Use reference images to help you draw. This is especially important if you are drawing a realistic object or character.
• Focus on getting the proportions right. You can refine and add details later.
• Practice hand-eye coordination. Draw straight and curved lines, as well as round shapes like circles and ellipses, to improve your hand-eye coordination.
• Vary the pressure of your pen to create different effects.
• Use light lines for your initial sketch. You can always go back and add solid lines and details later.
• Practice, practice, practice! Drawing is a skill that improves with time and effort, so don't be afraid to make mistakes.

Once you have drawn your object, you can move on to the next step of building your skeleton using the bone tool. Remember to take your time and enjoy the process of bringing your creation to life!

Build your skeleton

Now, you can use the bone tool to add structure to the object you've drawn. In this example, we'll be using an arm as our object. Certain objects call for certain types of animation tools, and not all of them can be animated so interchangeably. A body part with more direct, broader movements like an arm can be animated through tweening or using the bone tool. On the other hand, animating something with more intricate movements like a hand is best done through tweening or frame-by-frame animation.

Building a skeleton for an arm is relatively simple, as it only requires two to three bone joints. To make a skeleton, simply select the arm and drag the bones across it. These "bones" will appear as purple lines which will act as the ligaments to your object; they form the skeletal outline for your arm. Along with these ligaments come joints, which act as anchored points that you can interact with to manipulate the arm and make it move.

You'll want to start your skeleton at the base of your object, where the arm won't be moving, or at least not as fluidly. This will produce a joint with a red-line dot in the middle, which can be referred to as the anchor point. This is the base foundation that keeps your skeleton firm as you move it. It's best placed at the joining points of a body, like where a thigh connects to a torso, or in this case, a bicep connecting up to the shoulder.

An arm is a simple structure, but remember that when you are building a skeleton, it is best to follow an anatomically correct skeletal outline for reference. This is especially crucial if you're not proficient in anatomically accurate drawing and are going for a more realistic approach in your projects.

Pose your object

Now that you've drawn your object and built its skeleton, it's time to pose your object and bring it to life! This is the final step in animating your skeletal construction.

After creating a skeleton for your object, a new layer will be created on your timeline called an Armature Layer. This is where you'll be able to adjust your object's movement by adding in poses. Think of these poses as keyframes—by placing a pose on the timeline, your object will move according to the new position.

To create a sense of speed and fluidity in your animation, you can adjust the spacing between your poses. The shorter the length between poses, the faster your object will move, and vice versa. It's important to pay attention to timing and positioning to give your object a sense of weight and make its movements more believable. Adding in extra object parts through regular tweening can also help bring your creation to life.

For example, let's continue with the waving arm example. To create the illusion of a "bounce" in the wave, you can add another pose a short distance from the previous one and position the arm at a slight nod or angle. This technique is useful for adding extra details to your animation, such as breathing or colliding with a surface.

Remember to monitor your work using the Onion Skin Tool, located at the bottom of your timeline in the playback options tab. This will help you fine-tune your object's movements and ensure smooth and realistic transitions between poses.

By following these steps and experimenting with different poses, you'll be able to create dynamic and lifelike animations using the Bone Tool in Adobe Animate.

Frequently asked questions