I just searched for Frenet frame and I got a Norway website. I don’t understand its language but I can know its code.
http://www.ia.hiof.no/~borres/gb/ma-frames/p-frames.html
But there’s a point I don’t undestand,
that if use the fomula below
T=C’
B=T x C’’
N=T x B
then Frenet frame look like this picture:
but If use the fomula
T=C’
B=T x V
N=T x B
with V=(0.0 , 0.0 , 1.0 , 0.0) then frenet frame would change like this picture
I don’t understand. Please explain to me