[CST-2] butterfly division

[Peter Taylor]

> Doing some last minute revision - could someone please tell me what the
> weights are for butterfly subdivision? Thanks!

According to
http://graphics.stanford.edu/~dzorin/multires/butterfly/sig96_noimg.ps.gz
they are

          b
 c ________________ c
   \      /\      /
    \    /  \    /
     \  /    \  /
    a \/______\/ a
      /\      /\
     /  \    /  \
    /    \  /    \
   /______\/______\
  c       b         c

Weights: a = 1/2, b = 1/8, c = -1/16

Peter
=====
Peter Taylor
pjt33@cam.ac.uk