Original Post
As I read some 3D books, when we use vector to represent a point P, we will put the fourth value w - (x, y, z, w) where w is equal to 1. When we use vector to represent a direction, we will put (x, y, z, w) where w is equal to 0. As I read some books about Quaternion, their syntax is [w, v], where v is the vector. But I want to know the value of w in the vector is the same meaning of the value of w in the Quaternion? Is there any relationship?