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Recreating the Apple fireworks animation

· 21 min read
Mehmet Ademi
Mehmet Ademi
Business Developer
Jonny Burger
Jonny Burger
Chief Hacker

Learn how to create an animation that Apple has on its website during the holiday season with this beginner-friendly Remotion tutorial!

Video version​

This tutorial is also available as a video version:

Source code​

GitHub

Getting started​

Start a new Remotion project and select the blank template:

bash
npm init video --blank
bash
npm init video --blank

Composition setup​

A <Composition> defines the dimensions and duration of the video. In the src/Root.tsx file, adjust the width and height to the following:

src/Root.tsx
tsx
export const RemotionRoot: React.FC = () => {
  return (
    <>
      <Composition
        id="MyComp"
        component={MyComposition}
        durationInFrames={150}
        fps={30}
        width={1920}
        height={1080}
      />
    </>
  );
};
src/Root.tsx
tsx
export const RemotionRoot: React.FC = () => {
  return (
    <>
      <Composition
        id="MyComp"
        component={MyComposition}
        durationInFrames={150}
        fps={30}
        width={1920}
        height={1080}
      />
    </>
  );
};

Create a background​

Create a new file src/Background.tsx and return a background with linear gradient:

src/Background.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
 
export const Background: React.FC = () => {
  return (
    <AbsoluteFill
      style={{
        background: "linear-gradient(to bottom, #000021, #010024)",
      }}
    />
  );
};
src/Background.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
 
export const Background: React.FC = () => {
  return (
    <AbsoluteFill
      style={{
        background: "linear-gradient(to bottom, #000021, #010024)",
      }}
    />
  );
};

Add the created background to the <MyComposition/> component, which can be found in the file src/Composition.tsx. This file will contain all the components that you create in this tutorial.

src/Composition.tsx
tsx
export const MyComposition: React.FC = () => {
  return (
    <AbsoluteFill>
      <Background />
    </AbsoluteFill>
  );
};
src/Composition.tsx
tsx
export const MyComposition: React.FC = () => {
  return (
    <AbsoluteFill>
      <Background />
    </AbsoluteFill>
  );
};

This results in the following:

Render a dot​

Render a white dot by creating a new file src/Dot.tsx and return a centered circle.

src/Dot.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
 
export const Dot: React.FC = () => {
  return (
    <AbsoluteFill
      style={{
        justifyContent: "center",
        alignItems: "center",
      }}
    >
      <div
        style={{
          height: 14,
          width: 14,
          borderRadius: 14 / 2,
          backgroundColor: "#ccc",
        }}
      />
    </AbsoluteFill>
  );
};
src/Dot.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
 
export const Dot: React.FC = () => {
  return (
    <AbsoluteFill
      style={{
        justifyContent: "center",
        alignItems: "center",
      }}
    >
      <div
        style={{
          height: 14,
          width: 14,
          borderRadius: 14 / 2,
          backgroundColor: "#ccc",
        }}
      />
    </AbsoluteFill>
  );
};

Add the <Dot> in your main composition src/Composition.tsx:

src/Composition.tsx
tsx
export const MyComposition: React.FC = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Dot />
    </AbsoluteFill>
  );
};
src/Composition.tsx
tsx
export const MyComposition: React.FC = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Dot />
    </AbsoluteFill>
  );
};

Now we got a white dot on top of our background:

Animate the dot​

Let's apply some animation to the white dot we created above. We create another component called <Shrinking> in a new file src/Shrinking.tsx, which then wraps the dot in the main composition src/Composition.tsx.

src/Shrinking.tsx
tsx
import React from "react";
import { AbsoluteFill, interpolate, useCurrentFrame } from "remotion";
export const Shrinking: React.FC<{
  children: React.ReactNode;
}> = ({ children }) => {
  const frame = useCurrentFrame();
  return (
    <AbsoluteFill
      style={{
        scale: String(
          interpolate(frame, [60, 90], [1, 0], {
            extrapolateLeft: "clamp",
            extrapolateRight: "clamp",
          }),
        ),
      }}
    >
      {children}
    </AbsoluteFill>
  );
};
src/Shrinking.tsx
tsx
import React from "react";
import { AbsoluteFill, interpolate, useCurrentFrame } from "remotion";
export const Shrinking: React.FC<{
  children: React.ReactNode;
}> = ({ children }) => {
  const frame = useCurrentFrame();
  return (
    <AbsoluteFill
      style={{
        scale: String(
          interpolate(frame, [60, 90], [1, 0], {
            extrapolateLeft: "clamp",
            extrapolateRight: "clamp",
          }),
        ),
      }}
    >
      {children}
    </AbsoluteFill>
  );
};

Add the <Shrinking> component in your main composition src/Composition.tsx:

tsx
export const MyComposition: React.FC = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Shrinking>
        <Dot />
      </Shrinking>
    </AbsoluteFill>
  );
};
tsx
export const MyComposition: React.FC = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Shrinking>
        <Dot />
      </Shrinking>
    </AbsoluteFill>
  );
};

Now, you have some action to show. By using <Shrinking> in your main composition you have created a scale out effect:

Move the dot​

Next, create a component called <Move>. This component has a spring animation, which by default goes from zero to one, and has a duration of four seconds (durationInFrames: 120) in the code snippet below:

src/Move.tsx
tsx
import React from "react";
import {
  AbsoluteFill,
  interpolate,
  spring,
  useCurrentFrame,
  useVideoConfig,
} from "remotion";
 
export const Move: React.FC<{
  children: React.ReactNode;
}> = ({ children }) => {
  const { fps } = useVideoConfig();
  const frame = useCurrentFrame();
 
  const down = spring({
    fps,
    frame,
    config: {
      damping: 200,
    },
    durationInFrames: 120,
  });
 
  const y = interpolate(down, [0, 1], [0, -400]);
 
  return (
    <AbsoluteFill
      style={{
        translate: `0 ${y}px`,
      }}
    >
      {children}
    </AbsoluteFill>
  );
};
src/Move.tsx
tsx
import React from "react";
import {
  AbsoluteFill,
  interpolate,
  spring,
  useCurrentFrame,
  useVideoConfig,
} from "remotion";
 
export const Move: React.FC<{
  children: React.ReactNode;
}> = ({ children }) => {
  const { fps } = useVideoConfig();
  const frame = useCurrentFrame();
 
  const down = spring({
    fps,
    frame,
    config: {
      damping: 200,
    },
    durationInFrames: 120,
  });
 
  const y = interpolate(down, [0, 1], [0, -400]);
 
  return (
    <AbsoluteFill
      style={{
        translate: `0 ${y}px`,
      }}
    >
      {children}
    </AbsoluteFill>
  );
};

Add the <Move> component to your composition src/Composition.tsx. You get a nice animation by combining the effect of moving and shrinking by surrounding the shrinking dot in the <Move> component:

src/Composition.tsx
tsx
export const MyComposition = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Move>
        <Shrinking>
          <Dot />
        </Shrinking>
      </Move>
    </AbsoluteFill>
  );
};
src/Composition.tsx
tsx
export const MyComposition = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Move>
        <Shrinking>
          <Dot />
        </Shrinking>
      </Move>
    </AbsoluteFill>
  );
};

And up goes the dot:

Duplicate the moving dot​

Here it gets a little bit trickier, but the following steps are going to make your animation a lot more entertaining. First, you add a delay prop into the <Move> component and then change the frame parameter of your spring() function.

src/Move.tsx
tsx
import React from "react";
import {
  AbsoluteFill,
  interpolate,
  spring,
  useCurrentFrame,
  useVideoConfig,
} from "remotion";
 
export const Move: React.FC<{
  children: React.ReactNode;
  delay: number;
}> = ({ children, delay }) => {
  const { fps } = useVideoConfig();
  const frame = useCurrentFrame();
 
  const down = spring({
    fps,
    frame: frame - delay,
    config: {
      damping: 200,
    },
    durationInFrames: 120,
  });
 
  const y = interpolate(down, [0, 1], [0, -400]);
 
  return (
    <AbsoluteFill
      style={{
        translate: `0 ${y}px`,
      }}
    >
      {children}
    </AbsoluteFill>
  );
};
src/Move.tsx
tsx
import React from "react";
import {
  AbsoluteFill,
  interpolate,
  spring,
  useCurrentFrame,
  useVideoConfig,
} from "remotion";
 
export const Move: React.FC<{
  children: React.ReactNode;
  delay: number;
}> = ({ children, delay }) => {
  const { fps } = useVideoConfig();
  const frame = useCurrentFrame();
 
  const down = spring({
    fps,
    frame: frame - delay,
    config: {
      damping: 200,
    },
    durationInFrames: 120,
  });
 
  const y = interpolate(down, [0, 1], [0, -400]);
 
  return (
    <AbsoluteFill
      style={{
        translate: `0 ${y}px`,
      }}
    >
      {children}
    </AbsoluteFill>
  );
};

Now, let's create a <Trail> component. It takes some React children and duplicates them. The component adds a delay to each subsequent dot so they don't start all at once. Each dot will have a scale applied to it, so that each dot is smaller than the previous one.

Put the previously created <Move> component within the <Trail> component. The order is crucial here. Things are done from inside out:

  1. Apply a scale so that the dots become smaller over time.
  2. Apply the move animation.
  3. Apply a delay between the animation start of each dot by using Remotion's <Sequence> component.
src/Trail.tsx
tsx
import React from "react";
import { AbsoluteFill, Sequence } from "remotion";
import { Move } from "./Move";
 
export const Trail: React.FC<{
  amount: number;
  children: React.ReactNode;
}> = ({ amount, children }) => {
  return (
    <AbsoluteFill>
      {new Array(amount).fill(true).map((a, i) => {
        return (
          <Sequence from={i * 3}>
            <AbsoluteFill>
              <Move delay={0}>
                <AbsoluteFill
                  style={{
                    scale: String(1 - i / amount),
                  }}
                >
                  {children}
                </AbsoluteFill>
              </Move>
            </AbsoluteFill>
          </Sequence>
        );
      })}
    </AbsoluteFill>
  );
};
src/Trail.tsx
tsx
import React from "react";
import { AbsoluteFill, Sequence } from "remotion";
import { Move } from "./Move";
 
export const Trail: React.FC<{
  amount: number;
  children: React.ReactNode;
}> = ({ amount, children }) => {
  return (
    <AbsoluteFill>
      {new Array(amount).fill(true).map((a, i) => {
        return (
          <Sequence from={i * 3}>
            <AbsoluteFill>
              <Move delay={0}>
                <AbsoluteFill
                  style={{
                    scale: String(1 - i / amount),
                  }}
                >
                  {children}
                </AbsoluteFill>
              </Move>
            </AbsoluteFill>
          </Sequence>
        );
      })}
    </AbsoluteFill>
  );
};

In your main component, you now replace the <Move> component with the <Trail> component:

src/Composition.tsx
tsx
export const MyComposition = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Trail amount={4}>
        <Shrinking>
          <Dot />
        </Shrinking>
      </Trail>
    </AbsoluteFill>
  );
};
src/Composition.tsx
tsx
export const MyComposition = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Trail amount={4}>
        <Shrinking>
          <Dot />
        </Shrinking>
      </Trail>
    </AbsoluteFill>
  );
};

And this is how your animation with the duplicated dots should look like:

Duplicating markup and arranging it in a circle​

Now let's create a <Explosion> component. It takes children and renders them for example 10 times and applies a rotation to each instance. It's worth mentioning here that a full rotation amounts to 2π, while (i/AMOUNT) represents a factor between 0 and 1.

src/Explosion.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
 
const AMOUNT = 10;
 
export const Explosion: React.FC<{
  children: React.ReactNode;
}> = ({ children }) => {
  return (
    <AbsoluteFill>
      {new Array(AMOUNT).fill(true).map((_, i) => {
        return (
          <AbsoluteFill
            style={{
              rotate: (i / AMOUNT) * (2 * Math.PI) + "rad",
            }}
          >
            {children}
          </AbsoluteFill>
        );
      })}
    </AbsoluteFill>
  );
};
src/Explosion.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
 
const AMOUNT = 10;
 
export const Explosion: React.FC<{
  children: React.ReactNode;
}> = ({ children }) => {
  return (
    <AbsoluteFill>
      {new Array(AMOUNT).fill(true).map((_, i) => {
        return (
          <AbsoluteFill
            style={{
              rotate: (i / AMOUNT) * (2 * Math.PI) + "rad",
            }}
          >
            {children}
          </AbsoluteFill>
        );
      })}
    </AbsoluteFill>
  );
};

<Trail> gets put inside the <Explosion> component. Your main component (src/Composition.tsx) looks like this:

src/Composition.tsx
tsx
export const MyComposition = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Explosion>
        <Trail amount={4}>
          <Shrinking>
            <Dot />
          </Shrinking>
        </Trail>
      </Explosion>
    </AbsoluteFill>
  );
};
src/Composition.tsx
tsx
export const MyComposition = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Explosion>
        <Trail amount={4}>
          <Shrinking>
            <Dot />
          </Shrinking>
        </Trail>
      </Explosion>
    </AbsoluteFill>
  );
};

The animated explosion should look like this:

Cleanup​

You have created a bunch of files until now, let's put most of them together in one file called src/Dots.tsx. Extract <Explosion> and it's children into a new separate component called Dots.

src/Dots.tsx
tsx
import React from "react";
import { Sequence } from "remotion";
import { Dot } from "./Dot";
import { Explosion } from "./Explosion";
import { Shrinking } from "./Shrinking";
import { Trail } from "./Trail";
 
export const Dots: React.FC = () => {
  return (
    <Explosion>
      <Trail amount={4}>
        <Shrinking>
          <Sequence from={5}>
            <Dot />
          </Sequence>
        </Shrinking>
      </Trail>
    </Explosion>
  );
};
src/Dots.tsx
tsx
import React from "react";
import { Sequence } from "remotion";
import { Dot } from "./Dot";
import { Explosion } from "./Explosion";
import { Shrinking } from "./Shrinking";
import { Trail } from "./Trail";
 
export const Dots: React.FC = () => {
  return (
    <Explosion>
      <Trail amount={4}>
        <Shrinking>
          <Sequence from={5}>
            <Dot />
          </Sequence>
        </Shrinking>
      </Trail>
    </Explosion>
  );
};

Replace the <Explosion> with the new <Dots> component:

tsx
export const MyComposition = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Dots />
    </AbsoluteFill>
  );
};
tsx
export const MyComposition = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Dots />
    </AbsoluteFill>
  );
};

Nothing has changed on the animation itself:

Adding hearts and stars​

To make the animation more exciting, let's add some stars and hearts in different colors. To do this, we need to basically repeat the previous steps. Besides the <Dots>component, we'll add three more components in the next few steps.

Let's start with red hearts. First you render a red heart by creating a new file src/RedHeart.tsx and return a centered red heart emoji.

src/RedHeart.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
 
export const RedHeart: React.FC = () => {
  return (
    <AbsoluteFill
      style={{
        justifyContent: "center",
        alignItems: "center",
      }}
    >
      ❤️
    </AbsoluteFill>
  );
};
src/RedHeart.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
 
export const RedHeart: React.FC = () => {
  return (
    <AbsoluteFill
      style={{
        justifyContent: "center",
        alignItems: "center",
      }}
    >
      ❤️
    </AbsoluteFill>
  );
};

Effects like <Shrinking>, <Move> and <Explosion> need to be applied to that red heart. We do this in a new component called RedHearts.

Consider s that we need to add an offset to <RedHearts>, otherwise they would be positioned the same as the <Dots>.

We change the position by giving the red hearts a bigger radius than the dots, and apply a 100px translation. Also, we add a short delay of 5 frames to the <Move> component:

src/RedHearts.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
import { Explosion } from "./Explosion";
import { Move } from "./Move";
import { RedHeart } from "./RedHeart";
import { Shrinking } from "./Shrinking";
 
export const RedHearts: React.FC = () => {
  return (
    <Explosion>
      <Move delay={5}>
        <AbsoluteFill style={{ transform: `translateY(-100px)` }}>
          <Shrinking>
            <RedHeart />
          </Shrinking>
        </AbsoluteFill>
      </Move>
    </Explosion>
  );
};
src/RedHearts.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
import { Explosion } from "./Explosion";
import { Move } from "./Move";
import { RedHeart } from "./RedHeart";
import { Shrinking } from "./Shrinking";
 
export const RedHearts: React.FC = () => {
  return (
    <Explosion>
      <Move delay={5}>
        <AbsoluteFill style={{ transform: `translateY(-100px)` }}>
          <Shrinking>
            <RedHeart />
          </Shrinking>
        </AbsoluteFill>
      </Move>
    </Explosion>
  );
};

We do the same to get some yellow hearts in our animation:

src/YellowHeart.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
 
export const YellowHeart: React.FC = () => {
  return (
    <AbsoluteFill
      style={{
        justifyContent: "center",
        alignItems: "center",
      }}
    >
      💛
    </AbsoluteFill>
  );
};
src/YellowHeart.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
 
export const YellowHeart: React.FC = () => {
  return (
    <AbsoluteFill
      style={{
        justifyContent: "center",
        alignItems: "center",
      }}
    >
      💛
    </AbsoluteFill>
  );
};

For the yellow hearts we are going to change the position by applying a translation of 50px and adding a delay of 20 frames to the <Move> component:

src/YellowHearts.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
import { Explosion } from "./Explosion";
import { Move } from "./Move";
import { Shrinking } from "./Shrinking";
import { YellowHeart } from "./YellowHeart";
 
export const YellowHearts: React.FC = () => {
  return (
    <AbsoluteFill
      style={{
        rotate: "0.3rad",
      }}
    >
      <Explosion>
        <Move delay={20}>
          <AbsoluteFill
            style={{
              transform: `translateY(-50px)`,
            }}
          >
            <Shrinking>
              <YellowHeart />
            </Shrinking>
          </AbsoluteFill>
        </Move>
      </Explosion>
    </AbsoluteFill>
  );
};
src/YellowHearts.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
import { Explosion } from "./Explosion";
import { Move } from "./Move";
import { Shrinking } from "./Shrinking";
import { YellowHeart } from "./YellowHeart";
 
export const YellowHearts: React.FC = () => {
  return (
    <AbsoluteFill
      style={{
        rotate: "0.3rad",
      }}
    >
      <Explosion>
        <Move delay={20}>
          <AbsoluteFill
            style={{
              transform: `translateY(-50px)`,
            }}
          >
            <Shrinking>
              <YellowHeart />
            </Shrinking>
          </AbsoluteFill>
        </Move>
      </Explosion>
    </AbsoluteFill>
  );
};

Your main composition should look like this:



In addition to the dots and hearts let's also add stars.

Create a new file src/Star.tsx and return a centered star emoji.

src/Star.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
 
export const Star: React.FC = () => {
  return (
    <AbsoluteFill
      style={{
        justifyContent: "center",
        alignItems: "center",
        fontSize: 14,
      }}
    >
      ⭐
    </AbsoluteFill>
  );
};
src/Star.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
 
export const Star: React.FC = () => {
  return (
    <AbsoluteFill
      style={{
        justifyContent: "center",
        alignItems: "center",
        fontSize: 14,
      }}
    >
      ⭐
    </AbsoluteFill>
  );
};

Consider that we need to change the positioning of the stars, otherwise they would be on top of the <Dots>.

Let's give <Trail> an extraOffset prop, so the stars can start more outwards than the dots.

An extraOffset of 100 for the stars leads to the same circumference at the beginning and end as the red hearts have. Here is the adjusted <Trail>:

src/Trail.tsx
tsx
import React from "react";
import { AbsoluteFill, Sequence } from "remotion";
import { Move } from "./Move";
 
export const Trail: React.FC<{
  amount: number;
  extraOffset: number;
  children: React.ReactNode;
}> = ({ amount, extraOffset, children }) => {
  return (
    <AbsoluteFill>
      {new Array(amount).fill(true).map((a, i) => {
        return (
          <Sequence from={i * 3}>
            <AbsoluteFill
              style={{
                translate: `0 ${-extraOffset}px`,
              }}
            >
              <Move delay={0}>
                <AbsoluteFill
                  style={{
                    scale: String(1 - i / amount),
                  }}
                >
                  {children}
                </AbsoluteFill>
              </Move>
            </AbsoluteFill>
          </Sequence>
        );
      })}
    </AbsoluteFill>
  );
};
src/Trail.tsx
tsx
import React from "react";
import { AbsoluteFill, Sequence } from "remotion";
import { Move } from "./Move";
 
export const Trail: React.FC<{
  amount: number;
  extraOffset: number;
  children: React.ReactNode;
}> = ({ amount, extraOffset, children }) => {
  return (
    <AbsoluteFill>
      {new Array(amount).fill(true).map((a, i) => {
        return (
          <Sequence from={i * 3}>
            <AbsoluteFill
              style={{
                translate: `0 ${-extraOffset}px`,
              }}
            >
              <Move delay={0}>
                <AbsoluteFill
                  style={{
                    scale: String(1 - i / amount),
                  }}
                >
                  {children}
                </AbsoluteFill>
              </Move>
            </AbsoluteFill>
          </Sequence>
        );
      })}
    </AbsoluteFill>
  );
};

Effects like <Shrinking>, the new <Trail> and <Explosion> need to be applied to the star we created above. Additionally we also add some rotation. We do all of this in a new component called Stars:

src/Stars.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
import { Explosion } from "./Explosion";
import { Shrinking } from "./Shrinking";
import { Star } from "./Star";
import { Trail } from "./Trail";
 
export const Stars: React.FC = () => {
  return (
    <AbsoluteFill
      style={{
        rotate: "0.3rad",
      }}
    >
      <Explosion>
        <Trail extraOffset={100} amount={4}>
          <Shrinking>
            <Star />
          </Shrinking>
        </Trail>
      </Explosion>
    </AbsoluteFill>
  );
};
src/Stars.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
import { Explosion } from "./Explosion";
import { Shrinking } from "./Shrinking";
import { Star } from "./Star";
import { Trail } from "./Trail";
 
export const Stars: React.FC = () => {
  return (
    <AbsoluteFill
      style={{
        rotate: "0.3rad",
      }}
    >
      <Explosion>
        <Trail extraOffset={100} amount={4}>
          <Shrinking>
            <Star />
          </Shrinking>
        </Trail>
      </Explosion>
    </AbsoluteFill>
  );
};

Here is how the almost complete firework should look like:

Slow motion effect​

Lastly let's apply a slow motion effect to the firework. For this, create a new file src/SlowedTrail.tsx. It should contain a component called Slowed and a helper function remapSpeed() which will apply different speed levels to the firework. In the code snippet below a speed of 1.5 is applied until frame 20, afterwards the speed slows down to 0.5.

src/SlowedTrail.tsx
tsx
import React from "react";
import { Freeze, interpolate, useCurrentFrame } from "remotion";
 
// remapSpeed() is a helper function for the component <Slowed> that takes a frame number and a speed
const remapSpeed = ({
  frame,
  speed,
}: {
  frame: number;
  speed: (fr: number) => number;
}) => {
  let framesPassed = 0;
  for (let i = 0; i <= frame; i++) {
    framesPassed += speed(i);
  }
 
  return framesPassed;
};
 
export const Slowed: React.FC<{
  children: React.ReactNode;
}> = ({ children }) => {
  const frame = useCurrentFrame();
  const remappedFrame = remapSpeed({
    frame,
    speed: (f) =>
      interpolate(f, [0, 20, 21], [1.5, 1.5, 0.5], {
        extrapolateRight: "clamp",
      }),
  });
 
  return <Freeze frame={remappedFrame}>{children}</Freeze>;
};
src/SlowedTrail.tsx
tsx
import React from "react";
import { Freeze, interpolate, useCurrentFrame } from "remotion";
 
// remapSpeed() is a helper function for the component <Slowed> that takes a frame number and a speed
const remapSpeed = ({
  frame,
  speed,
}: {
  frame: number;
  speed: (fr: number) => number;
}) => {
  let framesPassed = 0;
  for (let i = 0; i <= frame; i++) {
    framesPassed += speed(i);
  }
 
  return framesPassed;
};
 
export const Slowed: React.FC<{
  children: React.ReactNode;
}> = ({ children }) => {
  const frame = useCurrentFrame();
  const remappedFrame = remapSpeed({
    frame,
    speed: (f) =>
      interpolate(f, [0, 20, 21], [1.5, 1.5, 0.5], {
        extrapolateRight: "clamp",
      }),
  });
 
  return <Freeze frame={remappedFrame}>{children}</Freeze>;
};

In the main component, wrap all moving dots, hearts and stars in the component <Slowed>. As you sure can tell by now, everything is very composable:

src/Composition.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
import { Background } from "./Background";
import { Dots } from "./Dots";
import { RedHearts } from "./RedHearts";
import { Slowed } from "./SlowedTrail";
import { Stars } from "./Stars";
import { YellowHearts } from "./YellowHearts";
 
export const MyComposition = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Slowed>
        <Dots />
        <RedHearts />
        <YellowHearts />
        <Stars />
      </Slowed>
    </AbsoluteFill>
  );
};
src/Composition.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
import { Background } from "./Background";
import { Dots } from "./Dots";
import { RedHearts } from "./RedHearts";
import { Slowed } from "./SlowedTrail";
import { Stars } from "./Stars";
import { YellowHearts } from "./YellowHearts";
 
export const MyComposition = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Slowed>
        <Dots />
        <RedHearts />
        <YellowHearts />
        <Stars />
      </Slowed>
    </AbsoluteFill>
  );
};

Your final firework should look like this:

Adding your animoji​

As the final step of this tutorial, we add your animoji on top of the firework. For the animoji you need to have an iPhone and a Mac. This is how you get it: On your iPhone in iMessage, record an animoji of yourself and send it to a friend. After you've done that, it will also appear in the Messages app on your Mac. Download your animoji there by right-clicking. Once you have done that, create a transparent version of your animoji. Just follow these points:

  1. Right-click your downloaded animoji
  2. Select "Services"
  3. Select "Encode Selected Video Files"
  4. Choose "Apple ProRes" in the settings dropdown
  5. Tick the box that says "Preserve Transparency".

A new encoded file of your animoji will be created. Give it a simple name like animoji.mov.

In addition to the src folder in your Remotion project, create a new one called public. Put your encoded video in this folder. You can then use FFmpeg to turn the encoded video into a series of frames:

  1. Change the current working directory to public: cd public
  2. Use this command: ffmpeg -i animoji.mov -pix_fmt rgba -start_number 0 frame%03d.png

Only assets that are being used by Remotion need to be in the public folder. You don't need the encoded video, so you can delete it after the frames have been extracted.

Here is a screenshot right before creating the series of frames:



Alright, so far you've prepared the animoji to be used in a new component called Animoji. You can import this series of frames by using the staticFile() API. The file name of each frame will help you to determine the current frame number.

src/Animoji.tsx
tsx
import React from "react";
import { AbsoluteFill, Img, staticFile, useCurrentFrame } from "remotion";
 
export const Animoji: React.FC = () => {
  const frame = useCurrentFrame();
 
  const src = `frame${(frame * 2).toString().padStart(3, "0")}.png`;
 
  return (
    <AbsoluteFill
      style={{
        justifyContent: "center",
        alignItems: "center",
        marginTop: 80,
      }}
    >
      <Img
        style={{
          height: 800,
        }}
        src={staticFile(src)}
      />
    </AbsoluteFill>
  );
};
src/Animoji.tsx
tsx
import React from "react";
import { AbsoluteFill, Img, staticFile, useCurrentFrame } from "remotion";
 
export const Animoji: React.FC = () => {
  const frame = useCurrentFrame();
 
  const src = `frame${(frame * 2).toString().padStart(3, "0")}.png`;
 
  return (
    <AbsoluteFill
      style={{
        justifyContent: "center",
        alignItems: "center",
        marginTop: 80,
      }}
    >
      <Img
        style={{
          height: 800,
        }}
        src={staticFile(src)}
      />
    </AbsoluteFill>
  );
};

Render the <Animoji> component in your main composition:

src/Composition.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
import { Animoji } from "./Animoji";
import { Background } from "./Background";
import { Dots } from "./Dots";
import { RedHearts } from "./RedHearts";
import { Slowed } from "./SlowedTrail";
import { Stars } from "./Stars";
import { YellowHearts } from "./YellowHearts";
 
export const MyComposition = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Slowed>
        <Dots />
        <RedHearts />
        <YellowHearts />
        <Stars />
      </Slowed>
      <Animoji />
    </AbsoluteFill>
  );
};
src/Composition.tsx
tsx
import React from "react";
import { AbsoluteFill } from "remotion";
import { Animoji } from "./Animoji";
import { Background } from "./Background";
import { Dots } from "./Dots";
import { RedHearts } from "./RedHearts";
import { Slowed } from "./SlowedTrail";
import { Stars } from "./Stars";
import { YellowHearts } from "./YellowHearts";
 
export const MyComposition = () => {
  return (
    <AbsoluteFill>
      <Background />
      <Slowed>
        <Dots />
        <RedHearts />
        <YellowHearts />
        <Stars />
      </Slowed>
      <Animoji />
    </AbsoluteFill>
  );
};

By doing all of this you have imported a transparent version of your animoji into your composition. You can run npm run build to export your video as MP4. Which should look like this:

Congrats on your programmatically generated video! 🎉