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Fractal Math, Chaos Theory & Research => (new) Theories & Research => Topic started by: cKleinhuis on February 01, 2015, 01:40:35 AM




Title: alternative power interpolation
Post by: cKleinhuis on February 01, 2015, 01:40:35 AM
found this on reddit/shadertoy:

http://nl.reddit.com/r/fractals/comments/2u9uo4/figured_out_how_to_transition_between_powers/

and shadertoy
https://www.shadertoy.com/view/lls3D7

:)


Title: Re: alternative power interpolation
Post by: Dinkydau on February 02, 2015, 10:42:51 PM
That's a nice discovery.


Title: Re: alternative power interpolation
Post by: DarkBeam on February 02, 2015, 11:09:36 PM
Very nice ;)


Title: Re: alternative power interpolation
Post by: cKleinhuis on February 02, 2015, 11:44:57 PM
what exactly has he done? removed the "mathematical correct" way to interpolate between powers to a more visual pleasing one ?!


Title: Re: alternative power interpolation
Post by: claude on February 03, 2015, 11:27:20 AM
Say you want to interpolate between the result sets from iterations of z \to z^2 + c and z \to z^3 + c.

One way would be to interpolate the power giving z \to z^{2(t-1) + 3t} + c with t from 0 to 1, but then you end up with fractional powers like 2.7123615245 which don't look so great (z^n with n integer wraps around a circle a whole number of times).

The other way presented in the article is to interpolate a sum giving z \to (t-1) z^2 + t z^3 + c, avoiding fractional powers entirely, while still starting and ending at the desired equations.

If it might help, a musical analogy: instead of a slide from C to G going through all microtonal pitches in between, it's like C fading out while G fades in.

Personally I think both methods are equally "mathematically correct", there are a lot of different ways to interpolate, and even with the same method there can be multiple routes (eg: on a sphere you could go the long way round).


Title: Re: alternative power interpolation
Post by: cKleinhuis on February 03, 2015, 11:34:08 AM
ah, i see, its basically the "interpolation hybrid" which interpolates lineary between two outcomes of different formulas, like

 z \to (t-1) (z^2 +c_1) +t (z^3 + c_2)

but using just the exponential term to lineary interpolate