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Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

HTML

              
                
              
            
!

CSS

              
                html,
body
  margin: 0
  padding: 0
canvas
  display: block
  
  
              
            
!

JS

              
                class Fire extends THREE.Object3D {
  constructor () {
    super()
    this.numParticles = 1000
  
    this.opts = {
      sparkLifecycle: 0.7,
      sparkStartSize: 10,
      sparkEndSize: 20,
      sparkDistanceScale: 1.4,
      
      flameMinHeight: 0.02,
      flameMaxHeight: 0.2,
      flamePeriod: 0.5,
      windStrength: 0.14,
      windFrequency: 0.5,
      
      color: 0x6e4d00, //0xffcf5c,
      endColor: 0x8e3920, //0xc0988c,
      
      opacity: 0.7,
      gravity: 0.05,
      
      // static - set at start
      baseWidth: 0.8 // angle - multiple of PI
    }
    
    var textureLoader = new THREE.TextureLoader()
    textureLoader.load('https://s3-us-west-2.amazonaws.com/s.cdpn.io/126747/snowflake_16x16.png', (texture) => {
      this.texture = texture
      this.system.material.uniforms.texture.value = texture
    })
  }

  init () {
    // make sure gravity points in world Y
    // http://stackoverflow.com/questions/35641875/three-js-how-to-find-world-orientation-vector-of-objects-local-up-vector
    var v3 = new THREE.Vector3();
    v3.copy( this.up ).applyQuaternion(this.getWorldQuaternion().inverse());
    
    const systemGeometry = new THREE.BufferGeometry()
    const systemMaterial = new THREE.ShaderMaterial({
      uniforms: {
        up: { type: 'v3', value: v3 },
        gravity: { type: 'f', value: this.opts.gravity },
        elapsedTime: { type: 'f', value: 0.0 },
        numParticles: { type: 'f', value: this.numParticles },
        color: { type: 'c', value: new THREE.Color(this.opts.color) },
        endColor: { type: 'c', value: new THREE.Color(this.opts.endColor) },
        flameMaxHeight: { type: 'f', value: this.opts.flameMaxHeight },
        flameMinHeight: { type: 'f', value: this.opts.flameMinHeight },
        flamePeriod: { type: 'f', value: this.opts.flamePeriod },
        windStrength: { type: 'f', value: this.opts.windStrength },
        windFrequency: { type: 'f', value: this.opts.windFrequency },
        sparkLifecycle: { type: 'f', value: this.opts.sparkLifecycle },
        sparkDistanceScale: { type: 'f', value: this.opts.sparkDistanceScale },
        sparkStartSize: { type: 'f', value: this.opts.sparkStartSize },
        sparkEndSize: { type: 'f', value: this.opts.sparkEndSize },
        opacity: { type: 'f', value: this.opts.opacity },
        texture: { type: 't', value: null }
      },
      transparent: true,
      //depthWrite: false,
      depthTest: false,
      // NOTE: don't use additive blending for light backgrounds
      // http://answers.unity3d.com/questions/573717/particle-effects-against-light-backgrounds.html
      blending: THREE.AdditiveBlending,
      vertexShader: `
        uniform float elapsedTime;
        uniform float numParticles;
        uniform float gravity;
        uniform vec3 up;
        
        uniform float sparkLifecycle;
        uniform float sparkDistanceScale;
        uniform float sparkStartSize;
        uniform float sparkEndSize;
        
        uniform float flameMaxHeight;
        uniform float flameMinHeight;
        uniform float flamePeriod;
        uniform float windStrength;
        uniform float windFrequency;

        attribute vec3 direction;
        attribute float uniqueness;
        attribute float particleIndex;

        #define PI 3.141592653589793238462643383279

        varying float vTime;

        void main( void ) {
          // unique duration
          float duration = sparkLifecycle + sparkLifecycle * uniqueness;

          // make time loop
          float particleOffset = (particleIndex / numParticles * duration);
          float time = mod(elapsedTime + particleOffset, duration);

          // store time as 0-1 for fragment shader
          vTime = time / duration;

          // apply "gravity" to fire
          vec3 vGravity = up * gravity * pow(vTime, 2.0);

          // move in direction based on elapsed time
          float flameHeight = mix(flameMinHeight, flameMaxHeight, uniqueness); 
          vec3 vDistance = flameHeight * direction * vTime;

          // close flame at top (0.5 is fully closed)
          vDistance.xz *= cos(mix(0.0, PI * flamePeriod, vTime));

          // apply some random horizonal wind
          vec3 vWind = sin((elapsedTime + vTime * uniqueness) * windFrequency * uniqueness) * cross(up, direction) * windStrength * uniqueness * vTime;

          // add all forces to get final position for this frame
          vec3 pos = position + vDistance + vGravity + vWind;

          // Set size based on frame and distance
          vec4 mvPosition = modelViewMatrix * vec4( pos, 1.0 );
          gl_PointSize = mix(sparkStartSize, sparkEndSize, vTime);
				  gl_PointSize = gl_PointSize * (sparkDistanceScale / length(mvPosition.xyz));
          
          // project position on screen
          gl_Position = projectionMatrix * modelViewMatrix * vec4(pos, 1.0);
        }

      `,
      fragmentShader: `
        uniform vec3 color;
        uniform vec3 endColor;
        uniform float opacity;
        uniform sampler2D texture;

        varying float vTime;
        
        void main() {
          vec4 texColor = texture2D(texture, gl_PointCoord);
          vec4 startColor = vec4(color, opacity);
          vec4 endColor = vec4(endColor, 0.0);
          gl_FragColor = texColor * mix(startColor, endColor, vTime);
        }
      `
    })

    // all flames start at 0,0,0
    const positions = new Float32Array(this.numParticles * 3)
    for (let i = 0; i < positions.length; i += 3) {
      positions[i] = 0
    }
    
    const direction = new Float32Array(this.numParticles * 3)
    for (let i = 0; i < direction.length; i += 3) {
      const phi = this.randCenter(Math.PI * this.opts.baseWidth)
      const theta = this.randCenter(Math.PI)
      // create normal vector in random direction
      const sphereCoord = THREE.Spherical(1, phi, theta)

      const v = new THREE.Vector3()
      v.setFromSpherical(sphereCoord)
      direction[i] = v.x
      direction[i + 1] = v.y
      direction[i + 2] = v.z
    }

    // push some uniqueness - because entropy...
    const uniqueness = new Float32Array(this.numParticles)
    for (let i = 0; i < this.numParticles; i++) {
      uniqueness[i] = Math.random()
    }
    
    // remember particle index
    const particleIndex = new Float32Array(this.numParticles)
    for (let i = 0; i < this.numParticles; i++) {
      particleIndex[i] = i
    }


    systemGeometry.addAttribute('position', new THREE.BufferAttribute(positions, 3))
    systemGeometry.addAttribute('direction', new THREE.BufferAttribute(direction, 3))
    systemGeometry.addAttribute('uniqueness', new THREE.BufferAttribute(uniqueness, 1))
    systemGeometry.addAttribute('particleIndex', new THREE.BufferAttribute(particleIndex, 1))
    
    systemGeometry.computeBoundingSphere()
    this.system = new THREE.Points(systemGeometry, systemMaterial)
    
    this.add(this.system)
  }

  update (delta, elapsed) {
    this.system.material.uniforms.elapsedTime.value = elapsed
  }
  
  updateOne (opt) {
    this.system.material.uniforms[opt].value = this.opts[opt]
  }
  
  updateColor (opt) {
    this.system.material.uniforms[opt].value = new THREE.Color(this.opts[opt])
  }

  randCenter (v) {
    return (v * (Math.random() - 0.5))
  }
}


/// INIT
const HEIGHT = window.innerHeight
const WIDTH = window.innerWidth

// Create the scene
const scene = new THREE.Scene()

// Create the camera
const aspectRatio = WIDTH / HEIGHT
const fieldOfView = 60
const nearPlane = 0.1
const farPlane = 10
const camera = new THREE.PerspectiveCamera(
  fieldOfView,
  aspectRatio,
  nearPlane,
  farPlane
)

// Create the renderer
const renderer = new THREE.WebGLRenderer({
  alpha: true,
  antialias: true
})

renderer.setPixelRatio(window.devicePixelRatio)
renderer.setClearColor(0x222222, 1)
renderer.setSize(WIDTH, HEIGHT)
document.documentElement.appendChild(renderer.domElement)

const ambientLight = new THREE.AmbientLight(0xffffff, 1.0)
scene.add(ambientLight)


const controls = new THREE.OrbitControls( camera, renderer.domElement );
controls.enableDamping = true;
controls.dampingFactor = 0.25;
controls.enableZoom = false;


const render = () => {
  var delta = clock.getDelta()
  var elapsed = clock.getElapsedTime()
  fire.update(delta, elapsed)
  controls.update()
  renderer.render(scene, camera)
  window.requestAnimationFrame(render)
}


//////////
// INIT
//////////


//camera.position.y = 1.8
camera.position.z = 0.5
const clock = new THREE.Clock()
const fire = new Fire()
fire.position.y = -.1
fire.rotation.z = Math.PI * 0//.5
fire.init()
scene.add(fire)
render()


// DAT GUI
////////////////////////

function add(opt, min, max) {
  return gui.add(fire.opts, opt, min, max)
     .onChange(x => fire.updateOne(opt))
}

function addColor(opt) {
  return gui.addColor(fire.opts, opt)
     .onChange(x => fire.updateColor(opt))
}

const gui = new dat.GUI({load: {
  "preset": "Fire",
  "closed": false,
  "remembered": {
    "Fire": {
      "0": Object.assign({}, fire.opts)
    },
    "Single flame": {
      "0": {
        "sparkLifecycle": 0.5,
        "sparkStartSize": 10.455715495342929,
        "sparkEndSize": 20.112616426756986,
        "sparkDistanceScale": 1.5,
        "flameMinHeight": 0,
        "flameMaxHeight": 0.1,
        "flamePeriod": 0.9,
        "windStrength": 0,
        "windFrequency": 0,
        "opacity": 0.2,
        "gravity": 0.04,
        "color": 7228672,
        "endColor": 3939347
      }
    },
    "Meteor": {
      "0": {
        "sparkLifecycle": 0.7000000000000001,
        "sparkStartSize": 49.08331922099915,
        "sparkEndSize": 1,
        "sparkDistanceScale": 0.8,
        "flameMinHeight": 0.34,
        "flameMaxHeight": 0.24,
        "flamePeriod": 0.5,
        "windStrength": 0,
        "windFrequency": 0,
        "opacity": 0.8,
        "gravity": 0.38,
        "color": 7228672,
        "endColor": 9320736
      }
    },
    "Nebula": {
      "0": {
        "sparkLifecycle": 5,
        "sparkStartSize": 12.60169348010161,
        "sparkEndSize": 11.528704487722269,
        "sparkDistanceScale": 1.4,
        "flameMinHeight": 0.04,
        "flameMaxHeight": 0,
        "flamePeriod": 0.6000000000000001,
        "windStrength": 1,
        "windFrequency": 0.09,
        "opacity": 0.7000000000000001,
        "gravity": -0.03,
        "color": 2490478,
        "endColor": 9314336
      }
    }
  },
  "folders": {}
}
});
gui.remember(fire.opts);
add('sparkLifecycle', 0, 5).step(0.1)
add('sparkStartSize', 1, 100)
add('sparkEndSize', 1, 100)
add('sparkDistanceScale', 0.1, 5).step(0.1)

add('flameMinHeight', 0.0, 1.0).step(0.01)
add('flameMaxHeight', 0.0, 1.0).step(0.01)
add('flamePeriod', 0.0, 2.0).step(0.1)
add('windStrength', 0.0, 1.0).step(0.01)
add('windFrequency', 0.0, 10.0).step(0.01)

add('opacity', 0.1, 1.0).step(0.1)
add('gravity', -1, 1).step(0.01)

addColor('color')
addColor('endColor')

gui.close()

              
            
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