Introduction 00:00

Particles are precisely what you expect from that name. They are very popular and can be used to achieve various effects such as stars, smoke, rain, dust, fire, and many other things.

The good thing with particles is that you can have hundreds of thousands of them on screen with a reasonable frame rate. The downside is that each particle is composed of a plane (two triangles) always facing the camera.

Creating particles is as simple as making a Mesh. We need a BufferGeometry, a material that can handle particles (PointsMaterial), and instead of producing a Mesh we need to create a Points.

Setup 01:11

The starter is only composed of a cube in the middle of the scene. That cube ensures that everything is working.

First particles 01:36

Let's get rid of our cube and create a sphere composed of particles to start.

Geometry

You can use any of the basic Three.js geometries. For the same reasons as for the Mesh, it's preferable to use BufferGeometries. Each vertex of the geometry will become a particle:

/**
 * Particles
 */
// Geometry
const particlesGeometry = new THREE.SphereGeometry(1, 32, 32)

PointsMaterial

We need a special type of material called PointsMaterial. This material can already do a lot, but we will discover how to create our own particles material to go even further in a future lesson.

The PointsMaterial has multiple properties specific to particles like the size to control all particles size and the sizeAttenuation to specify if distant particles should be smaller than close particles:

// Material
const particlesMaterial = new THREE.PointsMaterial({
    size: 0.02,
    sizeAttenuation: true
})

As always, we can also change those properties after creating the material:

const particlesMaterial = new THREE.PointsMaterial()
particlesMaterial.size = 0.02
particlesMaterial.sizeAttenuation = true

Points

Finally, we can create the final particles the same way we create a Mesh, but this time by using the Points class. Don't forget to add it to the scene:

// Points
const particles = new THREE.Points(particlesGeometry, particlesMaterial)
scene.add(particles)

That was easy. Let's customize those particles.