Could anybody tell me what is meant by the knot vector and how to find its value? I read in the book, the value is 0,0,0,1,1,1,4,4,6,6. Also, I think none of the curves-and-surfaces-for-CAGD related textbooks, most of them, I read from library, are not giving information, absolutely, of how to find the value of the knot vector. Well, I read 7 books already. How could I solve the basic B-spline and NURBS function if I couldn't find the value of the knot vector as them are required to solve the function?