Creating Particle Transitions in Three.js

For your particle transition effect with a face, you'll need a combination of techniques. Here's how you could approach this:

1. Creating the Initial Face Particles

You'll need to start by sampling points from a 3D model or image of a face:

JAVASCRIPTCopied
// Basic particle system setup
const particleCount = 10000;
const particles = new THREE.BufferGeometry();
const positions = new Float32Array(particleCount * 3);
const colors = new Float32Array(particleCount * 3);

// Sample points from your face model/image
// This could be done by:
// - Using depth data from an image
// - Sampling vertices from a 3D model
// - Using a point cloud from a scan

const material = new THREE.PointsMaterial({
  size: 0.05,
  vertexColors: true,
  transparent: true
});

const particleSystem = new THREE.Points(particles, material);
scene.add(particleSystem);

2. Particle Dispersion

For the dispersion effect, you'll need to store both the original positions and target positions:

JAVASCRIPTCopied
// Store original positions
const originalPositions = positions.slice();

// Create target positions (random dispersion)
const targetPositions = new Float32Array(particleCount * 3);
for (let i = 0; i < particleCount; i++) {
  targetPositions[i * 3] = (Math.random() - 0.5) * 10;
  targetPositions[i * 3 + 1] = (Math.random() - 0.5) * 10;
  targetPositions[i * 3 + 2] = (Math.random() - 0.5) * 10;
}

// Animation function
function animateDispersion(progress) {
  for (let i = 0; i < particleCount; i++) {
    positions[i * 3] = originalPositions[i * 3] + (targetPositions[i * 3] - originalPositions[i * 3]) * progress;
    positions[i * 3 + 1] = originalPositions[i * 3 + 1] + (targetPositions[i * 3 + 1] - originalPositions[i * 3 + 1]) * progress;
    positions[i * 3 + 2] = originalPositions[i * 3 + 2] + (targetPositions[i * 3 + 2] - originalPositions[i * 3 + 2]) * progress;
  }
  particles.attributes.position.needsUpdate = true;
}

3. Reassembly with Neon Glow

For the reassembly and neon glow effect:

JAVASCRIPTCopied
// Create side view positions
const sideViewPositions = new Float32Array(particleCount * 3);
// Fill with positions from side view of face

// For the neon glow effect, use a custom shader material
const glowMaterial = new THREE.ShaderMaterial({
  uniforms: {
    color: { value: new THREE.Color(0x00ffff) },
    pointTexture: { value: new THREE.TextureLoader().load('textures/glow.png') }
  },
  vertexShader: `
    attribute float size;
    varying vec3 vColor;
    void main() {
      vColor = color;
      vec4 mvPosition = modelViewMatrix * vec4(position, 1.0);
      gl_PointSize = size * (300.0 / -mvPosition.z);
      gl_Position = projectionMatrix * mvPosition;
    }
  `,
  fragmentShader: `
    uniform vec3 color;
    uniform sampler2D pointTexture;
    varying vec3 vColor;
    void main() {
      gl_FragColor = vec4(color, 1.0) * texture2D(pointTexture, gl_PointCoord);
    }
  `,
  blending: THREE.AdditiveBlending,
  depthTest: false,
  transparent: true
});

Recommended Approach

For your specific effect, I recommend:

1. Use Three.js Points for the particles - This is more efficient than individual meshes
2. GPGPU for complex animations - For more complex movement patterns, consider using GPGPU techniques with shaders
3. Tweening library - Use GSAP or Tween.js to handle the transitions between states

Helpful Resources

• Look into Bruno Simon's Three.js Journey course which covers particle systems
• Check out examples of point cloud animations
• For the neon glow, research bloom post-processing effects in Three.js

For the physics-based dispersion, you might want to add some noise or turbulence to make the movement more natural rather than just linear interpolation.