Animation

The animation component lets us animate and tween values including:

  • Component values (e.g., position, visible)
  • Component property values (e.g., light.intensity)

We can also tween values directly for better performance versus going through .setAttribute, such as by animating values:

  • On the object3D (e.g., object3D.position.y, object3D.rotation.z)
  • Directly within a component (e.g., components.material.material.color, components.text.material.uniforms.opacity.value),

For example, translating a box:

<a-box position="0 1.6 0" animation="property: position; to: 5 1.6 0; dur: 1500; easing: linear"></a-box>

Or orbiting a sphere in a 5-meter radius:

<a-entity rotation="0 0 0" animation="property: rotation; to: 0 360 0; loop: true; dur: 10000">
<a-entity position="5 0 0"></a-entity>
</a-entity>

Read more below for additional options and discovering how to properly animate different types of values.

API

Properties

Property Description Default Value Values
property Property to animate. Can be a component name, a dot-delimited property of a component (e.g., material.color), or a plain attribute.
isRawProperty Flag to animate an arbitrary object property outside of A-Frame components for better performance. If set to true, for example, we can set property to like components.material.material.opacity. If property starts with components or object3D, this will be inferred to true. false
from Initial value at start of animation. If not specified, the current property value of the entity will be used (will be sampled on each animation start). It is best to specify a from value when possible for stability. null
to Target value at end of animation. null
type Right now only supports color for tweening isRawProperty color XYZ/RGB vector values. ‘’
delay How long (milliseconds) to wait before starting. 0
dir Which dir to go from from to to. normal alternate, reverse
dur How long (milliseconds) each cycle of the animation is. 1000
easing Easing function of animation. To ease in, ease out, ease in and out. easeInQuad See easings
elasticity How much to bounce (higher is stronger). 400
loop How many times the animation should repeat. If the value is true, the animation will repeat infinitely. 0
round Whether to round values. false
startEvents Comma-separated list of events to listen to trigger a restart and play. Animation will not autoplay if specified. startEvents will restart the animation, use pauseEvents to resume it. If there are other animation components on the entity animating the same property, those animations will be automatically paused to not conflict. null
pauseEvents Comma-separated list of events to listen to trigger pause. Can be resumed with resumeEvents. null
resumeEvents Comma-separated list of events to listen to trigger resume after pausing. null
autoplay Whether or not the animation should autoplay. Should be specified if the animation is defined for the animation-timeline component. null
enabled If disabled, animation will stop and startEvents will not trigger animation start. true

Multiple Animations

The component’s base name is animation. We can attach multiple animations to one entity by name-spacing the component with double underscores (__):

<a-entity animation="property: rotation"
animation__2="property: position"
animation__color="property: material.color"></a-entity>

Easings

Easings define the accelerations and speed throughout the cycle of the animation.

easeIn easeOut easeInOut Others
easeInQuad easeOutQuad easeInOutQuad linear
easeInCubic easeOutCubic easeInOutCubic
easeInQuart easeOutQuart easeInOutQuart
easeInQuint easeOutQuint easeInOutQuint
easeInSine easeOutSine easeInOutSine
easeInExpo easeOutExpo easeInOutExpo
easeInCirc easeOutCirc easeInOutCirc
easeInBack easeOutBack easeInOutBack
easeInElastic easeOutElastic easeInOutElastic

Events

Property Description
animationbegin Animation began. Event detail contains name of animation.
animationcomplete Animation completed. Event detail contains name of animation.
animationcomplete__ Animation completed if animation has an ID (e.g., animation__click).

Members

Accessed as el.components.animation.<MEMBER>.

Member Description
animation anime.js object.
config Config passed to anime.js.

Animating on Events

We can use the startEvents property to animate upon events:

<a-entity id="mouseCursor" cursor="rayOrigin: mouse"></a-entity>

<a-entity
geometry="primitive: box"
material="color: red"
animation__mouseenter="property: components.material.material.color; type: color; to: blue; startEvents: mouseenter; dur: 500";
animation__mouseleave="property: components.material.material.color; type: color; to: red; startEvents: mouseleave; dur: 500";

Remix the Animating on Events Glitch.

Animating Different Types of Values

We’ll go over different cases of animating different types of values.

Component Values

We can animate a single-property component value (e.g., property: visible, we’ll go over booleans in a bit) or animate a property of a multi-property component using a dot . as a separator (e.g., property: light.intensity, property: material.color).

If the property is a vec3, that is also supported (e.g., property: someComponent.vec3Value; to: 5 5 5).

However, animating component values this way is not the most optimal way as it will invoke .setAttribute on each frame of the animation. For an animation here or there, it won’t be a big deal, but we can save time and memory by animating values directly.

A special note to try not to animate values of the geometry component as that will recreate the geometry on each tick. Rather animate scale if we want to animate the size.

Boolean Values

We can “animate” boolean values where the to value will be applied at the end of the animation. Like property: visible; from: false; to: true; dur: 1.

Direct Values through object3D and components

The animation component supports animating values directly through object3D or components.

For example, we can animate values on object3D like property: object3D.position.z; to: 5 which will tween the entity’s object3D.position.z value directly without calling .setAttribute; it’s the most direct way and lets us animate a single axis at a time. Note, for object3D.rotation, degrees are used.

Or we can animate values by reaching into components. For example, rather than animating property: material.opacity which would call .setAttribute on each frame, we can animate the opacity value directly with property: components.material.material.opacity. We use a dot-delimited path to walk the object tree to find the value we want to animate, and the animation process under the hood reduces down to changing a number.

Direct Color Values

We can animate three.js color values directly, but we’ll need to specify type: color. So rather than animating property: material.color, we can do property: components.material.material.color; type: color.

A note on color values, we can specify color values using hex, color names, hsl, or rgb (e.g., from: red; to: #FFCCAA or from: rgb(100, 100, 100); to: hsl(213, 100%, 70%))..

Using anime.js Directly

anime is a popular and powerful animation engine. The component prefers to do just basic tweening and touches the surface of what anime can do (e.g., timelines, motion paths, progress, seeking). If we need more animation features, create a separate component that invokes anime.js directly. anime is accessible via AFRAME.ANIME.

Read through and explore the anime.js documentation and website.

See Also