NOTE: This version of the documentation tracks unstable development happening on A-Frame’s
masterbranch. If you wish to try it out, grab the unstable build. Otherwise, head to the documentation for the current 0.7.0 version
Also check out the aframe-animation-component
We can add animations in A-Frame attaching an
<a-animation> element as a
child of the entity to animate.
As an introductory example, to define a 5-meter orbit on an entity about the Y-axis that takes 10 seconds, we can offset its position and animate the rotation of a parent entity. This animation starts with the initial rotation about the Y-axis of 0 degrees and goes around to 360 degrees. It’s defined with a duration of 10000 milliseconds, maintains the final value on each cycle of the animation, and loops indefinitely.
Here is an overview of animation attributes. We’ll go into more detail below.
|attribute||Attribute to animate. To specify a component attribute, use
|begin||Event name to wait on before beginning animation.||‘’|
|delay||Delay (in milliseconds) or event name to wait on before beginning animation.||0|
|direction||Direction of the animation (between
|dur||Duration in (milliseconds) of the animation.||1000|
|easing||Easing function of the animation. There are very many to choose from.||ease|
|end||Event name to wait on before stopping animation.||‘’|
|fill||Determines effect of animation when not actively in play. One of
|from||Starting value.||Current value.|
|repeat||Repeat count or
|to||Ending value. Must be specified.||None|
A-Frame’s animation system can animate different types of properties.
A-Frame has standard
vec3 components (i.e.,
scale). These components consist of three factors: X, Y, and Z. We can
pass three space-delimited numbers to the
to attributes just as we
would define them on an entity. In this case, the animation system will assume
we are animating a
For example, if we want to animate an entity going from one spot to another, we
can animate the
A-Frame has standard components that accept a single boolean value. Boolean values can be “animated” as well by flipping the boolean at the end of each animation cycle.
For example, we can define an animation that toggles off the visibility of an entity after 5 seconds.
We can animate numeric attributes as well. For example, we can animate the intensity of the light primitive.
We can animate any component property that has a color type. For example, we can animate a box from white to red.
We can animate a certain property of a multi-property component. To do so, we
select the component property using the dot syntax:
For example, to animate a cone’s top radius, we can select the
begin attribute defines when the animation should start playing.
This can either be a number, representing milliseconds to wait, or an event name to wait for. For example, we can define an animation that waits 2 seconds before scaling an entity.
Or we can define an animation that waits for the parent element to trigger an
fade before fading an entity.
direction attribute defines which way to animate between the starting
value and the final value.
When we define an alternating direction, the animation will go back and forth
to values like a yo-yo. Alternating directions only
take affect when we repeat the animation.
|alternate||On even-numbered cycles, animate from
|alternate-reverse||On odd-numbered cycles, animate from
easing attribute defines the easing function of the animation, which
ease. There are too many easing functions to list, but we can
implicitly explain them.
One possible value is
linear. And the basic easing functions are
Then there are more groups of easing functions. The above basic easing
functions prefix each group of easing functions. The groups of easing functions
For example, the
cubic group of easing functions would consist of
fill attribute defines the effect of animation when not actively in play.
fill as what values the animation sets on the entity before and/or
after each animation cycle. Below are the possible values for
|backwards||Before the animation starts, set the starting value to the
|both||Combine the effects of both backwards fill and forwards fill.|
|forwards||After the animation finishes, the final value will stay at the
|none||Before the animation starts, set the starting value to the initial value. After the animation finishes, reset the value to the initial value.|
repeat attribute defines how often the animation repeats. We call each
repeat of the animation a cycle. Repeat can either be a number that counts down
on each animation cycle until it reaches
0 at which point the animation will
end, or we can set
indefinite and the animation will loop
continuously until the animation is manually removed or stopped.
<a-animation> element emits a couple of events.
|animationend||Emitted when the animation finishes. In case of repeats, emitted when the repeat count reaches
|animationstart||Emitted immediately when the animation begins playing.|