easiest fnf psych engine wavy bg tutorial in existence

put this in the Lua file of the chart (if you already have a onCreatePost or onUpdate function just put it at the end of beginning and with some spacing)



function onCreatePost()
    initLuaShader("fart")

    setSpriteShader("background", "fart")
end

function onUpdate()
    setShaderFloat("background", "uTime", getSongPosition()/1000)
    setShaderFloat("background", "uWaveAmplitude", 0.01)
    setShaderFloat("background", "uSpeed", 2)
    setShaderFloat("background", "uFrequency", 5)
end



then on the folder of your mod on the Shaders folder add a file called fart.frag

open that file on notepad and put This text in it:




#pragma header
    //uniform float tx, ty; // x,y waves phase

    //modified version of the wave shader to create weird garbled corruption like messes
    uniform float uTime;

    /**
     * How fast the waves move over time
     */
    uniform float uSpeed;

    /**
     * Number of waves over time
     */
    uniform float uFrequency;

    /**
     * How much the pixels are going to stretch over the waves
     */
    uniform float uWaveAmplitude;

    vec2 sineWave(vec2 pt)
    {
        float x = 0.0;
        float y = 0.0;

        float offsetX = sin(pt.y * uFrequency + uTime * uSpeed) * (uWaveAmplitude / pt.x * pt.y);
        float offsetY = sin(pt.x * uFrequency - uTime * uSpeed) * (uWaveAmplitude / pt.y * pt.x);
        pt.x += offsetX; // * (pt.y - 1.0); // <- Uncomment to stop bottom part of the screen from moving
        pt.y += offsetY;

        return vec2(pt.x + x, pt.y + y);
    }

    void main()
    {
        vec2 uv = sineWave(openfl_TextureCoordv);
        gl_FragColor = texture2D(bitmap, uv);
    }