Function update

src/grass.js:279–282

(cameraPos)

      geometry.instanceCount = Math.floor(maxCount * THREE.MathUtils.clamp(d, 0, 1));
    },
    update(cameraPos) {
      uniforms.uCameraPos.value.copy(cameraPos);
      uniforms.uSunDir.value.copy(sunLight.position).normalize();
    },
  };
}