Animation
Note: This documentation is for the old 1.1.0 version of A-Frame. Check out the documentation for the current 1.6.0 version
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="-1 1.6 -5" animation="property: position; to: 1 8 -10; dur: 2000; easing: linear; loop: true" color="tomato"></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"> |
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" |
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> |
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.