cesium-examples/map/3d/code/snow.js

65 lines
2.1 KiB
JavaScript

/*
* @Descripttion:
* @version: 1.0
* @Author: zhangti
* @Date: 2019-10-15 18:02:44
* @LastEditors: sueRimn
* @LastEditTime: 2019-11-12 10:38:13
*/
/**
*
* 封装天气场景
* 雪天
*/
export default class Snow{
constructor(v){
this.collection = v.scene.postProcessStages;
this._snow = new Cesium.PostProcessStage({
name: 'czm_snow',
fragmentShader: this.getFS()
});
this.collection.add(this._snow);
v.scene.skyAtmosphere.hueShift = -0.8;
v.scene.skyAtmosphere.saturationShift = -0.7;
v.scene.skyAtmosphere.brightnessShift = -0.33;
v.scene.fog.density = 0.001;
v.scene.fog.minimumBrightness = 0.8;
}
getFS(){
return "uniform sampler2D colorTexture;\n\
varying vec2 v_textureCoordinates;\n\
\n\
float snow(vec2 uv,float scale)\n\
{\n\
float time = czm_frameNumber / 60.0;\n\
float w=smoothstep(1.,0.,-uv.y*(scale/10.));if(w<.1)return 0.;\n\
uv+=time/scale;uv.y+=time*2./scale;uv.x+=sin(uv.y+time*.5)/scale;\n\
uv*=scale;vec2 s=floor(uv),f=fract(uv),p;float k=3.,d;\n\
p=.5+.35*sin(11.*fract(sin((s+p+scale)*mat2(7,3,6,5))*5.))-f;d=length(p);k=min(d,k);\n\
k=smoothstep(0.,k,sin(f.x+f.y)*0.01);\n\
return k*w;\n\
}\n\
\n\
void main(void){\n\
vec2 resolution = czm_viewport.zw;\n\
vec2 uv=(gl_FragCoord.xy*2.-resolution.xy)/min(resolution.x,resolution.y);\n\
vec3 finalColor=vec3(0);\n\
float c = 0.0;\n\
c+=snow(uv,30.)*.0;\n\
c+=snow(uv,20.)*.0;\n\
c+=snow(uv,15.)*.0;\n\
c+=snow(uv,10.);\n\
c+=snow(uv,8.);\n\
c+=snow(uv,6.);\n\
c+=snow(uv,5.);\n\
finalColor=(vec3(c)); \n\
gl_FragColor = mix(texture2D(colorTexture, v_textureCoordinates), vec4(finalColor,1), 0.5); \n\
\n\
}\n\
";
}
remove(){
this._snow.destroy();
}
}