private class GenericTuple<T1, T2, T3>
{
    public T1 item1;
    public T2 item2;
    public T3 item3;

    public GenericTuple(T1 item1, T2 item2, T3 item3)
    {
        this.item1 = item1;
        this.item2 = item2;
        this.item3 = item3;
    }
}

public static List<GenericTuple<double, double, double>> DoTheMagic()
{
    int v1min = 0;
    int v1max = 1;
    double v1granularity = 0.05;
    double v2granularity = 0.05;
    double v3granularity = 0.05;

    List<GenericTuple<double, double, double>> returnee = new List<GenericTuple<double, double, double>>();

    for (double v1val = v1min; v1val <= v1max; v1val += v1granularity)
        for (double v2val = GetV2min(v1val); v2val <= GetV2max(v1val); v2val += v2granularity)
            for (double v3val = GetV3min(v1val, v2val); v3val <= GetV3max(v1val, v2val); v3val += v3granularity)
                returnee.Add(new GenericTuple<double, double, double>(v1val, v2val, v3val));


    return returnee;
}

private static int GetV2min(double v1val)
{
    throw new NotImplementedException();
}

private static int GetV2max(double v1val)
{
    throw new NotImplementedException();
}

private static int GetV3min(double v1val, double v2val)
{
    throw new NotImplementedException();
}

private static int GetV3max(double v1val, double v2val)
{
    throw new NotImplementedException();
}