水烟雾云

# vertexShader
uniform vec3 uColor;
uniform float uFrequency;
uniform float uScale;
uniform float uTim
varying float vElevation;

varying vec2 vUv
// highp -2^16-2^16
// mediump = -2^10-2^10
// lowp -2^8-2^8
precision highp float;
void main(){
    vec4 modelPosition = modelMatrix * vec4( position, 1.0 
    modelPosition.z += sin((modelPosition.x+uTime) * uFrequency)*uScale ;
    modelPosition.z += cos((modelPosition.y+uTime) * uFrequency)*uScale
    vElevation = modelPosition.z;
    gl_Position =  projectionMatrix * viewMatrix * modelPosition;
    vUv = u
}

# vertexShader

precision lowp float;
uniform float uWaresFrequency;
uniform float uScale;
uniform float uNoiseFrequency;
uniform float uNoiseScale;
uniform float uXzScale;
uniform float uTime;
uniform float uXspeed;
uniform float uZspeed;
uniform float uNoiseSpeed;

// 计算出的高度传递给片元着色器
varying float vElevation;

// 随机函数
float random (vec2 st) {
    return fract(sin(dot(st.xy,vec2(12.9898,78.233)))*43758.5453123);
}

// 旋转函数
vec2 rotate(vec2 uv, float rotation, vec2 mid)
{
    return vec2(
      cos(rotation) * (uv.x - mid.x) + sin(rotation) * (uv.y - mid.y) + mid.x,
      cos(rotation) * (uv.y - mid.y) - sin(rotation) * (uv.x - mid.x) + mid.y
    );
}

// 噪声函数
float noise (in vec2 _st) {
    vec2 i = floor(_st);
    vec2 f = fract(_st);

    // Four corners in 2D of a tile
    float a = random(i);
    float b = random(i + vec2(1.0, 0.0));
    float c = random(i + vec2(0.0, 1.0));
    float d = random(i + vec2(1.0, 1.0));

    vec2 u = f * f * (3.0 - 2.0 * f);

    return mix(a, b, u.x) +
            (c - a)* u.y * (1.0 - u.x) +
            (d - b) * u.x * u.y;
}


//	Classic Perlin 2D Noise
//	by Stefan Gustavson
//
vec4 permute(vec4 x)
{
    return mod(((x*34.0)+1.0)*x, 289.0);
}

vec2 fade(vec2 t)
{
    return t*t*t*(t*(t*6.0-15.0)+10.0);
}

float cnoise(vec2 P)
{
    vec4 Pi = floor(P.xyxy) + vec4(0.0, 0.0, 1.0, 1.0);
    vec4 Pf = fract(P.xyxy) - vec4(0.0, 0.0, 1.0, 1.0);
    Pi = mod(Pi, 289.0); // To avoid truncation effects in permutation
    vec4 ix = Pi.xzxz;
    vec4 iy = Pi.yyww;
    vec4 fx = Pf.xzxz;
    vec4 fy = Pf.yyww;
    vec4 i = permute(permute(ix) + iy);
    vec4 gx = 2.0 * fract(i * 0.0243902439) - 1.0; // 1/41 = 0.024...
    vec4 gy = abs(gx) - 0.5;
    vec4 tx = floor(gx + 0.5);
    gx = gx - tx;
    vec2 g00 = vec2(gx.x,gy.x);
    vec2 g10 = vec2(gx.y,gy.y);
    vec2 g01 = vec2(gx.z,gy.z);
    vec2 g11 = vec2(gx.w,gy.w);
    vec4 norm = 1.79284291400159 - 0.85373472095314 * vec4(dot(g00, g00), dot(g01, g01), dot(g10, g10), dot(g11, g11));
    g00 *= norm.x;
    g01 *= norm.y;
    g10 *= norm.z;
    g11 *= norm.w;
    float n00 = dot(g00, vec2(fx.x, fy.x));
    float n10 = dot(g10, vec2(fx.y, fy.y));
    float n01 = dot(g01, vec2(fx.z, fy.z));
    float n11 = dot(g11, vec2(fx.w, fy.w));
    vec2 fade_xy = fade(Pf.xy);
    vec2 n_x = mix(vec2(n00, n01), vec2(n10, n11), fade_xy.x);
    float n_xy = mix(n_x.x, n_x.y, fade_xy.y);
    return 2.3 * n_xy;
}


void main(){
    vec4 modelPosition = modelMatrix * vec4(position,1.0);

    float elevation = sin(modelPosition.x*uWaresFrequency+uTime*uXspeed)*sin(modelPosition.z*uWaresFrequency*uXzScale+uTime*uZspeed);

    elevation += -abs(cnoise(vec2(modelPosition.xz*uNoiseFrequency+uTime*uNoiseSpeed))) *uNoiseScale;

    vElevation = elevation;

    elevation *= uScale;



    modelPosition.y += elevation;

    gl_Position = projectionMatrix * viewMatrix *modelPosition;
}