How to add a Three.js Particle System to a 3D Game Rocket Engine with HTML and Javascrpt

Particle systems are a great way to add special visual effects to your 3D scenes, such as fire, smoke, or sparks. In this article, we will show you how to create a particle system for a rocket engine using the Three.js library.

First, you will need to create a geometry that will store the positions of the particles. This is done using the THREE.BufferGeometry object. Next, you will need to create an array of particle positions and initialize them to the origin (0, 0, 0). This is done using the Float32Array object.

Once you have the positions of the particles, you will need to add them to the buffer geometry using the addAttribute method. After that, you will need to create a material for the particles. This is done using the THREE.PointsMaterial object. The material is what gives the particles their visual appearance.

Next, you will create a particle system using the THREE.Points object. This object is what will be used to render the particle system. Finally, you will add the particle system to the scene using the add method.

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To animate the particle system, you will need to use the requestAnimationFrame function. This function is called repeatedly to update the particle positions and render the scene.

Keep in mind that this is just an overview of the process, and you will need to have some knowledge of Three.js and programming in general to implement it in your own projects.

Introduction

In this tutorial, we will be creating a particle system for a rocket exhaust using Three.js. A particle system is a technique used to simulate a variety of special visual effects like fire, smoke, and sparks.

Step 1: Create the particle geometry

First, we will create a THREE.BufferGeometry object that will be used to store the particle positions.

    
    let particleGeometry = new THREE.BufferGeometry();

Step 2: Create an array of particle positions

We will create an array of particle positions and initialize them to the origin (0, 0, 0).

    
    // Create an array of particle positions
    var particlePositions = new Float32Array(1000 * 3);

    for (var i = 0; i < 1000; i++) {
        // Set the x, y, and z coordinates for the particle

        var x = 0;
        var y = 0;
        var z = 0;
        particlePositions[i * 3 + 0] = x;
        particlePositions[i * 3 + 1] = y;
        particlePositions[i * 3 + 2] = z;
    }

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Step 3: Add the particle positions to the buffer geometry

We will add the particle positions to the buffer geometry using the addAttribute method.

    
    particleGeometry.addAttribute('position', 

             new THREE.BufferAttribute(particlePositions, 3));

Step 4: Create a material for the particles

We will create a THREE.PointsMaterial object that will be used to render the particles.

    
    var particleMaterial = new THREE.PointsMaterial({
        color: 0xffffff,
        size: 0.1
    });

Step 5: Create a particle system

We will create a THREE.Points object that will be used to render the particle system.

    
    var particleSystem = new THREE.Points(particleGeometry, particleMaterial);

Step 6: Add the particle system to the scene

We will add the particle system to the scene using the add method.

    
    scene.add(particleSystem);
    
 

Step 7: Animate the particle system

We will use the requestAnimationFrame function to animate the particle system.

    
    function animate() {
       

    requestAnimationFrame(animate);
   

    // Get the particle positions from the buffer geometry

    var positions = particleGeometry.attributes.position.array;

    for (var i = 0; i < 1000; i++) {

        // Assign a random speed to the particle
        var speed = Math.random() * 0.5;

        // Move the particle in the -z direction at the random speed
        positions[i * 3 + 2] -= speed;

        //expanding on x and y axis
        positions[i * 3 + 0] += (Math.random() - 0.5) * 0.08;
        positions[i * 3 + 1] += (Math.random() - 0.5) * 0.08;
        // Check if the particle has reached the reset point
        if (positions[i * 3 + 2] < -2) {
            // Reset the particle back to its starting position
            positions[i * 3 + 0] = RocketObject.position.x;
            positions[i * 3 + 1] = RocketObject.position.y;
            positions[i * 3 + 2] = RocketObject.position.z;
        }
    }

    // Update the particle positions in the buffer geometry
    particleGeometry.attributes.position.needsUpdate = true;
        renderer.render(scene, camera);

    }
    

    animate();

Quick Working Webpage Example

This code creates a particle system for a rocket engine using Three.js. It starts by defining global variables for the scene, camera, renderer, and spheres. Then it sets up the Three.js scene and camera, and creates a WebGL renderer with antialiasing and sets the size to the window's size. It also sets up orbital controls for the camera and adds event listeners for window resize, mouse click and mouse move. It creates a particle geometry and sets up an array of particle positions and then adds it to the buffer geometry. It then creates a material for the particles, creates a particle system, and adds it to the scene. The animateRocketExhaustParticles function is called to animate the particles to move in the negative Z direction while expanding on the X and Y axis and when they reach a certain distance it resets them to the starting point.