Flutter Magic: Build Your Own Particle System (and look like a wizard)

This article explains how to build a particle system in Flutter, creating effects like fire or explosions. It guides you through setting up particles, making them move, and drawing them on the screen using CustomPainter, adding dynamic visual effects to your apps. A particle system is a collection of tiny visual objects (particles) that behave together to create effects like fire, smoke, sparks, or explosions. In Flutter, a particle system usually involves:

Particles: The tiny objects (dots, shapes, or images).
Emitter: The source from which particles appear.
Behavior: Rules that tell particles how to move, change color, shrink, or vanish.
Renderer: The part that draws the particles on the screen every frame.

Step 1: Setup Particles

Each particle has:

Position: Where it is on the screen.
Velocity: How fast and in which direction it moves.
Color: Because explosions should not be boring.
Size: Tiny, medium, or “OMG that’s huge.”
Lifetime: How long it sticks around before vanishing.

Step 2: Summon Your Particles

Whenever the user taps the screen, we want a bunch of particles to burst out from that exact spot. We do this by taking the tap’s position as an Offset — basically the X and Y coordinates on the screen — and then generating particles around it with random directions, speeds, sizes, and colors.

Step 3: Make Them Move

Particles aren’t meant to sit around looking pretty — they zoom across the screen in random directions, slowly fade out, and eventually disappear. Think of this as a mini life story for each particle:

Born at the tap position.
Zooms in a random direction.
Fades gracefully.
Dies when its lifetime ends.

Step 4: Draw the Magic on the Screen

Flutter’s CustomPainter lets us draw each particle exactly where it should be, with the right color, size, and fading effect.

Final Step: Trigger the Explosion