shader

来源

   //shadertory：https://www.shadertoy.com/view/ctVGD1
   //shadertory：https://www.shadertoy.com/view/ml3GWs 

代码

	import { DoubleSide, ShaderChunk, ShaderMaterial } from "three";

export default function getFireMaterial() {
  //https://www.shadertoy.com/view/ctVGD1
  /**
   一个从玻璃花纹修改来的火焰特效
   shadertory：https://www.shadertoy.com/view/ctVGD1
   shadertory：https://www.shadertoy.com/view/ml3GWs 
   */
  const vertex = `
${ShaderChunk.logdepthbuf_pars_vertex}
bool isPerspectiveMatrix(mat4) {
    return true;
}

varying vec4 m_pos;
varying vec2 vUv;
varying vec3 _flame;

uniform float uTime;

vec2 hash( vec2 p ){
	p = vec2( dot(p,vec2(127.1,311.7)), dot(p,vec2(269.5,183.3)) );
	return -1.0 + 2.0*fract(sin(p)*43758.5453123);
}
float noise1( in vec2 p ){
    // noise function from IQ himself
    const float K1 = 0.366025404; // (sqrt(3)-1)/2;
    const float K2 = 0.211324865; // (3-sqrt(3))/6;

	vec2  i = floor( p + (p.x+p.y)*K1 );
    vec2  a = p - i + (i.x+i.y)*K2;
    float m = step(a.y,a.x); 
    vec2  o = vec2(m,1.0-m);
    vec2  b = a - o + K2;
	vec2  c = a - 1.0 + 2.0*K2;
    vec3  h = max( 0.5-vec3(dot(a,a), dot(b,b), dot(c,c) ), 0.0 );
	vec3  n = h*h*h*h*vec3( dot(a,hash(i+0.0)), dot(b,hash(i+o)), dot(c,hash(i+1.0)));
    return dot( n, vec3(70.0) );
}
float noise2(in vec2 p){
    return
        0.500*noise1(p*1.0)
       +0.250*noise1(p*2.0)
       +0.125*noise1(p*4.0)
       +0.063*noise1(p*8.0)
    ;
}
vec2 noise3(in vec2 p){
    return vec2(noise2(p), noise2(p + 20.0));
}

vec2 noise4(in vec2 p){
    return noise3(p + noise3(p));
}

vec2 transform(in vec2 p){
    return p + 0.2 * noise4(1.4 * p - vec2(0.0, uTime * 0.8));
}

vec3 ud(vec2 p) {
    p.x = abs(p.x);
    float q = p.x * (p.y * 11.0 + 1.7);
    p.x = max(p.x, q);
    return vec3(1.0, 0.1, 0.0) / pow(length(p), 5.0) * 0.000008;
}

void main () {
    vUv = uv;
    vec2 st = uv-.5;
     _flame = ud(transform(st * vec2(1.0, 0.5)));    
    vec3 newPosition = normal*vec3(0,0,0)+position;
    gl_Position = projectionMatrix * modelViewMatrix * vec4(newPosition, 1.0);

      ${ShaderChunk.logdepthbuf_vertex}
}
    `;

  // 片元着色器代码
  const fragment = `
${ShaderChunk.logdepthbuf_pars_fragment}
precision mediump float;


varying vec2 vUv;
varying vec3 _flame;



void main() {

  vec2 uv = vUv;

  vec3 color = vec3(0.,0.,1.);









  gl_FragColor = vec4(_flame,length(_flame));
  ${ShaderChunk.logdepthbuf_fragment}
}
    `;

  const uniforms = {
    uTime: { value: 1.0 },
  };
  const material = new ShaderMaterial({
    uniforms: {
      uTime: { value: 1.0 },
    },
    vertexShader: vertex,
    fragmentShader: fragment,
    side: DoubleSide,
    transparent: true,
    depthWrite:true,
    depthTest:true,
    alphaTest: 0.5

  });
  return material;
}

Mesh

  let geometry = new PlaneGeometry(1, 1, 50, 50);
    let material = getFireMaterial();

    this.geometry = geometry;
    this.material = material;

    let mesh = new Mesh(geometry, material);
    this.mesh = mesh;
    let mesh2 = mesh.clone();
    mesh2.rotation.y = Math.PI / 2;
    this.add(mesh, mesh2);

动画

	  let loop = () => {
      requestAnimationFrame(loop);
      if ( this.material) {
        this.material.uniforms.uTime.value += 0.01;
      }
    };
    loop();

效果展示