vec2 normal_st = vec2(gl_FragCoord.x * 0.005, vPosition.y) * vec2(1000 * 2);
// vec2 normal_st = vec2(random(vDistance), random(vDistance))/vec2(u_resolution);
vec3 normal_pos = vec3(normal_st * 5.0, 1.0 * 0.5);

// vec3 pos_xz = vPosition * vec3(1.0, 0.0, 1.0);
// vec3 distance = pos_xz + vec3(0.15);
vec3 normal_noise = vec3(noise(normal_pos));
vec3 modifiedNormal = normal * normal_noise * vec3(0.5);
normal = modifiedNormal;