public int size;
public float speed;

private byte[] volume;
private byte[] shifted;

public bool widthShift, heightShift, depthShift;

private int widthOffset = 0;
private int heightOffset = 0;
private int depthOffset = 0;

private float time = 0;
private int cube;

void Start()
{
    volume = new byte[size * size * size];
    shifted = new byte[size * size * size];

    cube = size * size * size;

    for (int x = 0; x < size; x++)
        for (int y = 0; y < size; y++)
            for(int z = 0; z < size; z++)
                volume[x + y * size + z * size * size] = (x == 0 || y == 0 || z == 0) ? (byte)1 : (byte)0;
}

void Update()
{
    time += Time.fixedDeltaTime * speed;

    if (time > 1)
    {
        time = 0;

        widthOffset = (widthOffset >= size) ? 0 : widthOffset;
        heightOffset = (heightOffset >= size) ? 0 : heightOffset;
        depthOffset = (depthOffset >= size) ? 0 : depthOffset;

        if (widthShift)
            widthOffset++;
        else
            widthOffset = 0;

        if (heightShift)
            heightOffset++;
        else
            heightOffset = 0;

        if (depthShift)
            depthOffset++;
        else
            depthOffset = 0;

        Shift(widthOffset, heightOffset, depthOffset);
    }
}

void Shift(int xOff, int yOff, int zOff)
{
    for (int x = 0; x < size; x++)
        for (int y = 0; y < size; y++)
            for(int z = 0; z < size; z++)
            {
                int i = ((x + xOff) + (y + yOff) * size + (z + zOff) * size * size);
                i = (i >= cube) ? (i - cube) : i;

                shifted[x + y * size + z * size * size] = volume[i];
            }
}

void OnDrawGizmos()
{
    if(Application.isPlaying)
        for(int x = 0; x < size; x++)
            for(int y = 0; y < size; y++)
                for(int z = 0; z < size; z++)
                {
                    Gizmos.color = (shifted[x + y * size + z * size * size] == 1) ? new Color32(0, 255, 0, 255) : new Color32(255, 0, 0, 4);
                    Gizmos.DrawWireCube(new Vector3(x + 0.5f, y + 0.5f, z + 0.5f), new Vector3(0.95f, 0.95f, 0.95f));
                }
}

void Shift(int xOff, int yOff, int zOff)
{
    for (int x = 0; x < size; x++)
        for (int y = 0; y < size; y++)
            for(int z = 0; z < size; z++)
            {
                int nx = (x + xOff) % size;
                int ny = (y + yOff) % size;
                int nz = (z + zOff) % size;
                int i = (nx + ny * size + nz * size * size);

                shifted[x + y * size + z * size * size] = volume[i];
            }
}