dc-sdk/modules/material/shader/thirdpart/GrassMaterial.glsl

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);

  //Make thatch patterns
  float verticalNoise = czm_snoise(vec2(st.x * 100.0, st.y * 20.0)) * 0.02;
  float horizontalNoise = czm_snoise(vec2(st.x * 20.0, st.y * 100.0)) * 0.02;
  float stripeNoise = min(verticalNoise, horizontalNoise);

  color.rgb += stripeNoise;

  material.diffuse = color.rgb;
  material.alpha = color.a;

  return material;
}