HTML5 Canvas水面下太阳特效
1、新建html文档。
2、书写hmtl代码。
<div id="container"></div>
<div>HTML5 Canvas水面下太阳特效-适用于高版本浏览器</div>
3、书写css代码。
<style>
body {
margin: 0;
padding: 0;
}
#container {
position: fixed;
}
</style>
4、书写并添加js代码。
script src="js/three.min.js"></script>
<script id="vertexShader" type="x-shader/x-vertex">
void main() {
gl_Position = vec4( position, 1.0 );
}
</script>
<script id="fragmentShader" type="x-shader/x-fragment">
uniform vec2 u_resolution;
uniform float u_time;
const float NOISE_SIZE = 3.; // The size of the noise. Essentially the multiplier for the noise UV. Smaller = bigger
const float INTENSITY = 20.; // The intensity of the displacement
const float REFLECTION_INTENSITY = 4.; // The intensity of the rellowish reflections.
const int octaves = 2; // the number of octaves to generate in the FBM noise
const float seed = 43758.5453123; // A random seed :)
vec2 random2(vec2 st, float seed){
st = vec2( dot(st,vec2(127.1,311.7)),
dot(st,vec2(269.5,183.3)) );
return -1.0 + 2.0*fract(sin(st)*seed);
}
float noise(vec2 st, float seed) {
vec2 i = floor(st);
vec2 f = fract(st);
vec2 u = f*f*(3.0-2.0*f);
return mix( mix( dot( random2(i + vec2(0.0,0.0), seed ), f - vec2(0.0,0.0) ),
dot( random2(i + vec2(1.0,0.0), seed ), f - vec2(1.0,0.0) ), u.x),
mix( dot( random2(i + vec2(0.0,1.0), seed ), f - vec2(0.0,1.0) ),
dot( random2(i + vec2(1.0,1.0), seed ), f - vec2(1.0,1.0) ), u.x), u.y);
}
float fbm1(in vec2 _st, float seed) {
float v = 0.0;
float a = 0.5;
vec2 shift = vec2(100.0);
// Rotate to reduce axial bias
mat2 rot = mat2(cos(0.5), sin(0.5),
-sin(0.5), cos(0.50));
for (int i = 0; i < octaves; ++i) {
v += a * noise(_st, seed);
_st = rot * _st * 2.0 + shift;
a *= 0.4;
}
return v + .4;
}
float pattern(vec2 uv, float seed, float time, inout vec2 q, inout vec2 r) {
q = vec2( fbm1( uv + vec2(0.0,0.0), seed ),
fbm1( uv + vec2(5.2,1.3), seed ) );
r = vec2( fbm1( uv + 4.0*q + vec2(1.7 - time / 2.,9.2), seed ),
fbm1( uv + 4.0*q + vec2(8.3 - time / 2.,2.8), seed ) );
float rtn = fbm1( uv + 4.0*r, seed );
return rtn;
}
mat2 rotate(float angle) {
return mat2(cos(angle), -sin(angle), sin(angle), cos(angle));
}
void main() {
vec2 uv = (gl_FragCoord.xy - 0.5 * u_resolution.xy) / u_resolution.y;
// Generate our displacement map
vec2 _uv = uv * NOISE_SIZE;
vec2 q = vec2(0.);
vec2 r = vec2(0.);
float pattern = pattern(_uv, seed, u_time/2., q, r);
uv += (.5 - pattern) / INTENSITY; // modulate the main UV coordinates by the pattern
// uv -= .5 / INTENSITY; // This just recenters the UV coords after the distortion
float len = length(uv) + .01;
float field = len+0.05*(-1.0*u_time / 5.); // The distance field from the middle to the edge
float ripple;
ripple = sin(field*80.0) * .5 * r.x * pattern + 1.; // The ripple pattern
ripple += smoothstep(0.2,.0,len); // Adding a core gradient to the sun. Essentially this is just a smoothed version of the distance field
ripple *= smoothstep(0.3,.9,clamp(1. - len * 1.5,0.0,1.0)); // Vignette the sun, making it smaller than infinity
ripple -= fract(ripple * 8.) / 100.; // Adds a nice sort of reflective element
vec3 colour = vec3(.2, .3, .4); // the basic colour
colour += ripple * length(r) * vec3(1., 1., .8); // ripple times sun colour
colour += (1. - pattern * REFLECTION_INTENSITY * .5) * smoothstep(0.0,.7,clamp(1. - len * 1.5,0.0,1.0)) * vec3(-.2, -.1, 0.); // vignette and reflection
colour += (1. - pattern * REFLECTION_INTENSITY * 2.) * smoothstep(0.5,.9,clamp(1. - len * 1.5,0.0,1.0)) * vec3(-.2, -.1, 0.); // vignette and reflection 2 - this is essentially a more intense, but reduced radius version of the previous one.
gl_FragColor = vec4(colour, 1.);
}
</script>
5、代码整体结构。
6、查看效果。
