Cesium 自定义Material 系列 （十九）

对于fade 圆效果 我们先定义一下他的interface, 方便使用的人知道他的调用参数

export interface PMaterialFade{

color?: any,

speed?: number,

}

对于fade 圆我们叫 MaterialFade

```javascript

import { MaterialProperty } from "./MaterialProperty";

const defaultOption: any = {

color: new Cesium.Color(1.0, 0.0, 0.0, 0.5),

speed: 1

}

export class MaterialFade extends MaterialProperty {

protected _getType(option: any): string {

return "MaterialFade"

}

constructor(option = defaultOption) {

super(MaterialFade.prototype, defaultOption, option);

}

protected _getTranslucent(material: any) {

return material.uniforms.color.alpha < 1.0;

}

protected getSource(option: any): string {

return `

uniform vec4 color;

uniform float speed;

czm_material czm_getMaterial(czm_materialInput materialInput){

czm_material material = czm_getDefaultMaterial(materialInput);

material.diffuse = 1.5 * color.rgb;

vec2 st = materialInput.st;

float dis = distance(st, vec2(0.5, 0.5));

float per = fract(czm_frameNumber * speed / 1000.0);

 更多参考 https://xiaozhuanlan.com/topic/1520798634