Peter Popov wrote:

> But... but... you only need to scale the spline so that the range
> [0,0] to [1,1] maps onto the rectangle formed by a point and the next
> one you want your spline to pass through...

Please find enclosed a photo comparing the cubic spline, the #init_spline, and
the COSINE SPLINE.

The cubic spline is a pain because:
1) You have to make up two points before and after: in coding something like a
walk cycle, that's about another 12-16 points that have to be retyped every time
you make a little tweak.
2) It wildly varies from the range of the points.  Look at the image: if I were
keyframing a walk cycle with a cubic spline, I'd have a leg that sometimes bends
backwards +45 degrees, when I had coded in a range of [-10,-125]. It would be a
herculean effort to get this not to violate the range--and then it would be a
bear to edit as I gradually improved the walk cycle--a process that might
involve dozens of iterations. Not only do I have to type in extra numbers, but
it varies from the range in ways that makes it useless unless you are:

A) in need of a perfectly smooth, elegant camera path.
B) really making a curve that is replaceable by the cosine function itself.

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