[Algorithms] Re: Flip component

[Casey M. <gd...@fu...>]

> If I've decomposed a matrix into the form T F R U K U'as described by =
> Ken Shoemake in Graphics Gems IV and as used in decomp_affine() in the =
> Max SDK and I wish to interpolate it, which is all fine except for I'm =
> not sure how I should properly handle the F 'flip' component in the =
> interpolation?

I roll that into the scaling term.  I figure that the natural
interpretation of an inverted object interpolating into an uninverted
object, or vice versa, is to pass through infinitesimality, which is the
state of an object having no volume, which is a word I just made up
because I don't know what the real word is.  But suffice to say it
interpolates through 0 scale.

Also, be careful with decomp_affine() if your MAX version isn't >= 4.
They bollocks'd it up in < 4 (which is pretty scary considering that they
basically just cut and pasted the code AFAICT).  I switched to doing my
own decomposition back then, so I can't say for sure that it's fixed now,
but I assume it is.

- Casey