Cesium 自定义Material 系列 （十五）

• 对于绿地纹理 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 PMaterialGrass{
• grassColor?: any,
• dirtColor?: any,
• patchiness?: number
• }

• 对于绿地纹理我们叫 MaterialGrass

```javascript

import { MaterialProperty } from "./MaterialProperty";
const defaultOption: PMaterialGrass = {
grassColor: new Cesium.Color(0.25, 0.4, 0.1, 1.0),
dirtColor: new Cesium.Color(0.1, 0.1, 0.1, 1.0),
patchiness: 1.5
}
//草地效果
export class MaterialGrass extends MaterialProperty {
protected _getType(option: any): string {
return "MaterialGrass"
}
constructor(option = defaultOption) {
super(MaterialGrass.prototype, defaultOption, option);
}
protected _getTranslucent(material: any) {
var uniforms = material.uniforms
return uniforms.grassColor.alpha < 1.0 || uniforms.dirtColor.alpha < 1.0
}
protected getSource(option: any): string {
return `
uniform vec4 grassColor;
uniform vec4 dirtColor;
uniform float patchiness;

• czm_material czm_getMaterial(czm_materialInput materialInput){
• czm_material material = czm_getDefaultMaterial(materialInput);
•  
• vec2 st = materialInput.st;
• float noise1 = (czm_snoise(st * patchiness * 1.0)) * 1.0;
• float noise2 = (czm_snoise(st * patchiness * 2.0)) * 0.5;
• float noise3 = (czm_snoise(st * patchiness * 4.0)) * 0.25;
• float noise = sin(noise1 + noise2 + noise3) * 0.1;
•  
• vec4 color = mix(grassColor, dirtColor, noise);

 更多参考 https://xiaozhuanlan.com/topic/9430125687