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<title>纸屑飞舞</title>
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body{
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padding: 0;
overflow: hidden;
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<script src="js/three.js"></script>
<script src="js/OrbitControls.js"></script>
<script src="js/GPUComputationRenderer.js"></script>
<div class="wrapper" id="wrapper"></div>
<script id="simulation_vel" type="x-shader/x-fragment">
//
// Description : Array and textureless GLSL 2D/3D/4D simplex
// noise functions.
// Author : Ian McEwan, Ashima Arts.
// Maintainer : ijm
// Lastmod : 20110822 (ijm)
// License : Copyright (C) 2011 Ashima Arts. All rights reserved.
// Distributed under the MIT License. See LICENSE file.
// https://github.com/ashima/webgl-noise
//
vec3 mod289(vec3 x) {
return x - floor(x * (1.0 / 289.0)) * 289.0;
}
vec4 mod289(vec4 x) {
return x - floor(x * (1.0 / 289.0)) * 289.0;
}
vec4 permute(vec4 x) {
return mod289(((x*34.0)+1.0)*x);
}
vec4 taylorInvSqrt(vec4 r){
return 1.79284291400159 - 0.85373472095314 * r;
}
float snoise(vec3 v) {
const vec2 C = vec2(1.0/6.0, 1.0/3.0) ;
const vec4 D = vec4(0.0, 0.5, 1.0, 2.0);
// First corner
vec3 i = floor(v + dot(v, C.yyy) );
vec3 x0 = v - i + dot(i, C.xxx) ;
// Other corners
vec3 g = step(x0.yzx, x0.xyz);
vec3 l = 1.0 - g;
vec3 i1 = min( g.xyz, l.zxy );
vec3 i2 = max( g.xyz, l.zxy );
// x0 = x0 - 0.0 + 0.0 * C.xxx;
// x1 = x0 - i1 + 1.0 * C.xxx;
// x2 = x0 - i2 + 2.0 * C.xxx;
// x3 = x0 - 1.0 + 3.0 * C.xxx;
vec3 x1 = x0 - i1 + C.xxx;
vec3 x2 = x0 - i2 + C.yyy; // 2.0*C.x = 1/3 = C.y
vec3 x3 = x0 - D.yyy; // -1.0+3.0*C.x = -0.5 = -D.y
// Permutations
i = mod289(i);
vec4 p = permute( permute( permute(
i.z + vec4(0.0, i1.z, i2.z, 1.0 ))
+ i.y + vec4(0.0, i1.y, i2.y, 1.0 ))
+ i.x + vec4(0.0, i1.x, i2.x, 1.0 ));
// Gradients: 7x7 points over a square, mapped onto an octahedron.
// The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)
float n_ = 0.142857142857; // 1.0/7.0
vec3 ns = n_ * D.wyz - D.xzx;
vec4 j = p - 49.0 * floor(p * ns.z * ns.z); // mod(p,7*7)
vec4 x_ = floor(j * ns.z);
vec4 y_ = floor(j - 7.0 * x_ ); // mod(j,N)
vec4 x = x_ *ns.x + ns.yyyy;
vec4 y = y_ *ns.x + ns.yyyy;
vec4 h = 1.0 - abs(x) - abs(y);
vec4 b0 = vec4( x.xy, y.xy );
vec4 b1 = vec4( x.zw, y.zw );
//vec4 s0 = vec4(lessThan(b0,0.0))*2.0 - 1.0;
//vec4 s1 = vec4(lessThan(b1,0.0))*2.0 - 1.0;
vec4 s0 = floor(b0)*2.0 + 1.0;
vec4 s1 = floor(b1)*2.0 + 1.0;
vec4 sh = -step(h, vec4(0.0));
vec4 a0 = b0.xzyw + s0.xzyw*sh.xxyy ;
vec4 a1 = b1.xzyw + s1.xzyw*sh.zzww ;
vec3 p0 = vec3(a0.xy,h.x);
vec3 p1 = vec3(a0.zw,h.y);
vec3 p2 = vec3(a1.xy,h.z);
vec3 p3 = vec3(a1.zw,h.w);
//Normalise gradients
vec4 norm = taylorInvSqrt(vec4(dot(p0,p0), dot(p1,p1), dot(p2, p2), dot(p3,p3)));
p0 *= norm.x;
p1 *= norm.y;
p2 *= norm.z;
p3 *= norm.w;
// Mix final noise value
vec4 m = max(0.6 - vec4(dot(x0,x0), dot(x1,x1), dot(x2,x2), dot(x3,x3)), 0.0);
m = m * m;
return 42.0 * dot( m*m, vec4( dot(p0,x0), dot(p1,x1), dot(p2,x2), dot(p3,x3) ) );
}
vec3 snoiseVec3( vec3 x ){
float s = snoise(vec3( x ));
float s1 = snoise(vec3( x.y - 19.1 , x.z + 33.4 , x.x + 47.2 ));
float s2 = snoise(vec3( x.z + 74.2 , x.x - 124.5 , x.y + 99.4 ));
vec3 c = vec3( s , s1 , s2 );
return c;
}
// via: https://petewerner.blogspot.jp/2015/02/intro-to-curl-noise.html
vec3 curlNoise( vec3 p ){
const float e = 0.1;
float n1 = snoise(vec3(p.x, p.y + e, p.z));
float n2 = snoise(vec3(p.x, p.y - e, p.z));
float n3 = snoise(vec3(p.x, p.y, p.z + e));
float n4 = snoise(vec3(p.x, p.y, p.z - e));
float n5 = snoise(vec3(p.x + e, p.y, p.z));
float n6 = snoise(vec3(p.x - e, p.y, p.z));
float x = n2 - n1 - n4 + n3;
float y = n4 - n3 - n6 + n5;
float z = n6 - n5 - n2 + n1;
const float divisor = 1.0 / ( 2.0 * e );
return normalize( vec3( x , y , z ) * divisor );
}
uniform float timer;
uniform float delta;
uniform float speed;
uniform float factor;
uniform float evolution;
uniform float radius;
void main() {
vec2 uv = gl_FragCoord.xy / resolution.xy;
vec4 c = texture2D( posTex, uv );
vec4 oldVel = texture2D( velTex, uv );
vec3 pos = c.xyz;
float life = oldVel.a;
float s = life / 100.0;
float speedInc = 1.0;
vec3 v = factor * speedInc * delta * speed * ( curlNoise( .2 * pos) );
pos += v;
life -= 0.3;
if( life <= 0.0) {
pos = texture2D( defTex, uv ).xyz;
life = 100.0;
}
gl_FragColor = vec4( pos - c.xyz, life );
}
</script>
<script id="simulation_pos" type="x-shader/x-fragment">
void main() {
vec2 uv = gl_FragCoord.xy / resolution.xy;
vec4 tmpPos = texture2D( posTex, uv );
vec3 pos = tmpPos.xyz;
vec4 tmpVel = texture2D( velTex, uv );
vec3 vel = tmpVel.xyz;
pos += vel;
gl_FragColor = vec4( pos, 0.0 );
}
</script>
<script id="simulation_def" type="x-shader/x-fragment">
void main() {
vec2 uv = gl_FragCoord.xy / resolution.xy;
vec4 tmpPos = texture2D( defTex, uv );
gl_FragColor = vec4( tmpPos.rgb, 0.0 );
}
</script>
<script id="vs-particles" type="x-shader/x-vertex">
attribute float aNum;
attribute float aRandom;
// attribute vec2 aPosUv
attribute vec3 aColor;
uniform sampler2D posMap;
uniform sampler2D velMap;
uniform float size;
uniform float timer;
uniform vec3 boxScale;
uniform float meshScale;
uniform mat4 shadowMatrix;
varying vec3 vPosition;
varying vec3 vColor;
varying vec4 vShadowCoord;
mat3 calcLookAtMatrix(vec3 vector, float roll) {
vec3 rr = vec3(sin(roll), cos(roll), 0.0);
vec3 ww = normalize(vector);
vec3 uu = normalize(cross(ww, rr));
vec3 vv = normalize(cross(uu, ww));
return mat3(uu, ww, vv);
}
void main() {
vec2 posUv;
posUv.x = mod(aNum, (size - 1.0));
posUv.y = float(aNum / (size - 1.0));
posUv /= vec2(size);
vec4 cubePosition = texture2D( posMap, posUv );
vec4 cubeVelocity = texture2D( velMap, posUv );
float alpha = cubeVelocity.a / 100.0;
float scale = 0.025 * 4.0 * (1.0 - alpha) * alpha;
mat4 localRotationMat = mat4( calcLookAtMatrix( cubeVelocity.xyz, 0.0 ) );
vec3 modifiedVertex = (localRotationMat * vec4( position * scale * aRandom * (vec3(1.0)) * boxScale * meshScale, 1.0 ) ).xyz;
vec3 modifiedPosition = modifiedVertex + cubePosition.xyz;
gl_Position = projectionMatrix * modelViewMatrix * vec4( modifiedPosition, 1.0 );
vPosition = modifiedPosition;
// via: line 7 in https://github.com/mrdoob/three.js/blob/dev/src/renderers/shaders/ShaderChunk/shadowmap_vertex.glsl
vShadowCoord = shadowMatrix * modelMatrix * vec4( modifiedPosition, 1. );
vColor = aColor;
}
</script>
<script id="fs-particles" type="x-shader/x-fragment">
varying vec3 vPosition;
varying vec3 vColor;
varying vec4 vShadowCoord;
uniform sampler2D shadowMap;
uniform vec2 shadowMapSize;
uniform float shadowBias;
uniform float shadowRadius;
// uniform sampler2D projector;
uniform vec3 lightPosition;
uniform vec2 resolution;
float bias;
// via: https://github.com/mrdoob/three.js/blob/dev/src/renderers/shaders/ShaderChunk/packing.glsl
const float UnpackDownscale = 255. / 256.; // 0..1 -> fraction (excluding 1)
const vec3 PackFactors = vec3( 256. * 256. * 256., 256. * 256., 256. );
const vec4 UnpackFactors = UnpackDownscale / vec4( PackFactors, 1. );
float unpackRGBAToDepth( const in vec4 v ) {
return dot( v, UnpackFactors );
}
float texture2DCompare( sampler2D depths, vec2 uv, float compare ) {
return step( compare, unpackRGBAToDepth( texture2D( depths, uv ) ) );
}
float getShadow( sampler2D shadowMap, vec2 sha
