I made a #fractal #zoom #seamless #loop thing. Formula is Mandelbrot set modified to have power 2.005 instead of 2, coloured with additive blending of an orbit trap on the negative real axis (cycling between red, green, blue depending on iteration number).

The center point of the zoom is preperiodic point with preperiod 645 and period 12 (this fact was used to refine the coordinates to be more precise). Iteration count was 3000.

The zoom factor for the loop (both rotation and scaling) was found by overlaying two copies and fiddling with sliders until it lined up again.

Probably too much motion blur and not enough samples for anti-aliasing (256 per pixel), but it took almost 2 hours to render this 2 second thing...

@mathr Yeah, damn. 3000 iterations is no joke. What kind of CPU are you rendering on? What software do you use?

@artemis this was on GPU, AMD Radeon RX 580, using GLSL written for the Fragmentarium shader programming environment (3Dickulus FragM fork, with some minor patches of my own applied, though I don't think they were relevant in this instance).

GLSL doesn't have native double precision transcendental functions (need: sqrt exp log atan cos sin), so they have to be implemented by hand (luckily someone else already did most of it). But they are also pretty slow.


@mathr Oh wow, you're doing it in straight up GLSL? That's super interesting. I've done a bit of that using Shadron, but I'll check out Fragmentarium. Thanks!

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