Space, coordinates, and the magic Quaternion

## Where is where? In our daily life, when someone asked for the help about how to reach the place they want to go, we would answer them like "walk toward **north** and turn **left** at the first corner", and here we use some kind of coordinate system to represent the *relativity* of position in the world we are. And in our virtual world inside the computer, it would be awesome if we could use the same **north** and **left** concepts. But since the computer only knows 0 and 1, there are lots…