flow.glsl

float getPath(float progress) {
    float scale = 1.5;
    float p = (progress + 42.) * (1. / scale);
    // float sin1 = sin(p * 0.1) * 5.;
    // float sin2 = sin(2.2 * p * 0.1 + 5.52) * 2.5;
    // float sin3 = sin(2.9 * p * 0.2 + 0.93) * 1.2;
    // float sin4 = sin(4.6 * p * 0.2 + 8.94) * 0.5;
    
    float sin1 = sin(p * 0.1) * 5.;
    float sin2 = sin(p * 0.22 + 5.52) * 2.5;
    float sin3 = sin(p * 0.58 + 0.93) * 1.2;
    float sin4 = sin(p * 0.92 + 8.94) * 0.5;
    return (sin1 + sin2 + sin3 + sin4) * scale * 2.2;
    // return sin(progress);
}

vec3 flow(vec3 position, float time, float offset, float flowOffset) {
    vec2 point = vec2(getPath(time), -time * depth);
    vec2 normal = vec2(-time * depth, -getNormal(time));
    normal = normalize(normal);
    offset *= (sin(time) * sin(time * 2.) + 1.5) * 0.25;
    offset *= 18. * flowOffset;
    offset += sin(time) * sin(time * 2.) * 0.12;
    vec3 current = vec3(point.x, 0., point.y);
    current.xz += normal * offset;
    float height = 1. * ((sin(position.x) + sin(position.z)) * 0.5);
    height += 0.5 * ((sin(position.x * 2.) + sin(position.z * 1.5)) * 0.5);
    current.y += height * .2;
    return current;
}