Transitions
Transitions allow you to customize the way scenes transition from one into another. A transition is an animation performed at the beginning of the scene. It can modify the context of both the current and the previous scene.
Before we start
Make sure your project contains at least two scenes. In this example, we've
prepared firstScene.tsx
and secondScene.tsx
, and configured our project to
display one after the other. We'll be setting up our transitions in the second
scene.
Make sure to put something different in both scenes to easier see the transitions.
my-animation/
└─ src/
├─ scenes/
│ ├─ firstScene.tsx
│ └─ secondScene.tsx
└─ project.ts
Pre-made transitions
Motion Canvas comes with a set of common transitions in a form of easy-to-use
generators. To use them, yield*
the transition generator at the beginning of
the new scene:
export default makeScene2D(function* (view) {
// set up the scene:
view.add(/* your nodes here */);
// perform a slide transition to the left:
yield* slideTransition(Direction.Left);
// proceed with the animation
yield* waitFor(3);
});
Make sure to add nodes to the view before yielding the transition generator. Otherwise, your scene will remain empty until the transition ends.
All available transitions are listed below:
slideTransition
public slideTransitiondirection: Directionduration?: number: ThreadGenerator
public slideTransitionorigin: Originduration?: number: ThreadGenerator
Perform a transition that slides the scene in the given direction.
Parameters
direction: Direction
The direction in which to slide.
duration?: number
The duration of the transition.
zoomInTransition
public zoomInTransitionarea: BBoxduration: number = 0.6: ThreadGenerator
Perform a transition that zooms in on a given area of the scene.
Parameters
zoomOutTransition
public zoomOutTransitionarea: BBoxduration: number = 0.6: ThreadGenerator
Perform a transition that zooms out from a given area of the scene.
Parameters
fadeTransition
public fadeTransitionduration: number = 0.6: ThreadGenerator
Perform a transition that fades between the scenes.
Parameters
duration: number = 0.6
The duration of the transition.
waitTransition
public waitTransitionduration: number = 0.6previousOnTop: SignalValueboolean = true: ThreadGenerator
Perform a transition that doesn't do anything.
This is useful when you want to achieve a transition effect by animating objects in the scenes. It will overlay the scenes on top of each other for the duration of the transition.
Parameters
duration: number = 0.6
The duration of the transition.
previousOnTop: SignalValueboolean = true
Whether the previous scene should be rendered on top.
Custom transitions
You can use the useTransition
function
to implement custom transitions. It allows you to specify two callbacks that
will modify the contexts of the current and previous scene respectively. The
value it returns is a callback that you need to call once you finish the
transition.
The transition template looks as follows:
// set up the transition
const endTransition = useTransition(
currentContext => {
// modify the context of the current scene
},
previousContext => {
// modify the context of the previous scene
},
);
// perform animations
// finish the transition
endTransition();
Here's how you could implement a simple slide transition:
export function* slideTransition(
direction: Direction = Direction.Top,
duration = 0.6,
): ThreadGenerator {
const size = useScene().getRealSize();
const position = size.getOriginOffset(direction).scale(2);
const previousPosition = Vector2.createSignal();
const currentPosition = Vector2.createSignal(position);
// set up the transition
const endTransition = useTransition(
// modify the context of the current scene
ctx => ctx.translate(currentPosition.x(), currentPosition.y()),
// modify the context of the previous scene
ctx => ctx.translate(previousPosition.x(), previousPosition.y()),
);
// perform animations
yield* all(
previousPosition(position.scale(-1), duration),
currentPosition(Vector2.zero, duration),
);
// finish the transition
endTransition();
}
Animate when transitioning
By default, Motion Canvas will transition to the next scene once the generator
of the current scene has reached the end. In this case, the scene will freeze
for the duration of the transition. You can use the
finishScene
function to trigger the transition
early, allowing the animation to continue while transitioning:
export default makeScene2D(function* (view) {
yield* animationOne();
// trigger the transition early:
finishScene();
// continue animating:
yield* animationTwo();
});