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