public float CalculateDistance(Vector Pos1, Vector Pos2)
{
    float dx = Pos2.X - Pos1.X;
    float dy = Pos2.Y - Pos1.Y;
    float dz = Pos2.Z - Pos1.Z;
    return (float)Math.Sqrt(dx * dx + dy * dy + dz * dz);
}

注意：传入参数Vector的namespace为CounterStrikeSharp.API.Modules.Utils