Title: Question about Formula Post by: M Benesi on June 24, 2010, 08:44:43 PM Jesse,
I'm pretty sure I saw you mention using someone's streamlined formula for calculating Mandelbulbs, and I wanted to compare it to something I just threw together. Do you have a link to the thread with the formula, or know what I should search for? You could also glance at the following code and tell me if it is the same... but that may be more complicated. :D Code: r1=sqrt (sqr(sy) + sqr(sz)); // sx, sy, and sz are the starting x, y, and z components of the iteration Title: Re: Question about Formula Post by: Jesse on June 24, 2010, 09:26:32 PM Hmm, the only thing what comes into my mind is a conversation with David Makin about his implementation of formulas for Ultrafractal.
So you could search for "MMFwip3D.ufm" for the code, should the code be for the common mandelbulbs? Title: Re: Question about Formula Post by: M Benesi on June 24, 2010, 10:08:42 PM Lol.
Jesse- it gives me your message about searching for "MMFwip3D.ufm" when I search for it. :D Hilarious. Maybe it was somewhere else. I recall someone mentioning using someone's algebraic "faster" formula in some software... and I know the complex-triplex method I used above speeds things up nicely (especially for lower powers, or for higher powers if you sqr(sqr(sqr(X))) for z^8, etc...). Title: Re: Question about Formula Post by: Jesse on June 24, 2010, 10:29:34 PM You could also try it on google or use "MMFwip3D.zip" instead. :)
David uses a fast method for the integer powers in that file. Then there are the pure non-trig versions like these: http://www.fractalforums.com/3d-fractal-generation/true-3d-mandlebrot-type-fractal/msg8680/#msg8680 (http://www.fractalforums.com/3d-fractal-generation/true-3d-mandlebrot-type-fractal/msg8680/#msg8680) Title: Re: Question about Formula Post by: M Benesi on June 25, 2010, 07:45:09 AM Thanks Jesse, downloaded it (google pointed me back to here...). Ok.. that is fricken long. Never find the formula in there. NM... I might ask around later. The algebraic formulas are similar to the complex triplex I am using, except the complex triplex lets you go a bit faster, perhaps (unless my initial implementation of algebraic versions was incorrect or inefficient) . I noticed drop offs in performance above z^4 or 5 for algebraic write outs (compared to trig versions) but the performance of the complex triplex still (barely) exceeds that of trig formulas at z^13... and can be improved even further by the old sqr(sqr(sqr(z))) trick (thats z^8 in 3 squares (3 multiplications) instead of 8 multiplications...). |