March 13, 2007
Ok so im looking into more curve math – yes I’m nuts, no im not going to show you. Most of it is over my head but im slowly understanding it, like NURB’s which I finally worked out the algorithm!! Which is kinda cool. But now for the life of me cant get my head around the recursive ‘N’ function of B-Splines i.e the Basis fn – Ni,p So:
You have p =#(1,2,3,4,5) which are you control points and t which are basically a segment in this array infact either non-uniform or uniform eg. t=#(0,.25,.5,.75,1) Now what I dont get is Ni,p because basically if t[0,1] is within you segments eg. if t = .12 then its within segment 0,1 right and so it equals 1 and if not then 0 but its always 1 unless p or p[(p.count)] when it equals 0. Its basically a step fn but its always one – i dunno I there must be more to it!
Ni,0(u) = if u[i] <= u <u[i]+1 then 1 else 0 – so if u (t) is within its segment it equals 1 else 0.
edit: i think i get it.