▲ 78 points
back
29 comments
If you like this kind of zoom into the Mandelbrot set, check out this[1] zoom to 2^1116 from a few years ago (which is also available in 4k). The final ~2/5 of the zoom is probably the trippiest part of the Mandelbrot set I've ever seen, with a repeating "evil eye (nazar)"/"eye of sauron" motif[2] of incredible complexity.
Very nice. Thanks for sharing.
Like many others here I am sure, I was quite obsessed with fractals way back, fractint was awesome, and I did spend quite some time writing an integer math fractal generator in assembly on my AtariST back then (I remember enjoying just how many registers I could use on M68k compared to my friends that were working with x86 and how it made things so much simpler, I really enjoyed M68k assembly)
When I first found XaoS in later years it was amazing, thinking that you could actually zoom in real time (!) and it's nice to see that some programs are still around allowing you to do fractals.
It would be interesting to know which would be the fastest way to calculate them nowadays, if on the CPU or on the GPU (I think in both cases one would have to roll their own high precision math for deep zooms)
(edit) found a post on the Fractal Extreme blog discussing GPU math, it is from 2012 though, I wonder if the intervening 4 years have changed the author's opinion on this.
https://randomascii.wordpress.com/2012/03/28/fractal-and-cry...
I think it is no question that GPU's handle fractal renders significantly better than the CPU does. If you are rendering a fractal properly each pixel can be computed separately from all others, a problem that is perfect for the massive parallel multiprocessor.
I would even go far to say that with current GPU hardware rendering fractals is "solved" in terms of realtime capability. see: https://www.shadertoy.com/results?query=fractal
I think fractals are still awesome despite being pretty simple these days. They are an excellent gateway into doing programing on the GPU. I think they are exactly the type awe inspiring programs that younger students should be shown.
A lack of arbitrary precision makes GPUs unsuitable for deeper Mandelbrot zoom levels, so "solved" is overstating it.
how many levels are you talking about?
I agree the worse floating point precision of GPUs puts them at a disadvantage but they still do better for massively parallel problems like fractal renders. (http://www.bealto.com/mp-mandelbrot_benchmarks.html)
GPUs are happiest when doing float precision, which is 24 bits.
Most GPUs can, at reduced speed, do double precision, which is 53 bits.
The maximum precision for this zoom movie is 960 bits.
So, unless you write code to compose high-precision math operations out of double-precision math then the GPU cannot even participate. And once you do that you will find that the GPU's speed advantage is mostly or entirely lost.
CPUs can't do 960 bit operations either.
- CPUs can do 64x64 multiplies that give 128-bit results. GPUs cannot.
- CPUs can do add-with-carry. GPUs cannot.
That means that GPUs are not very good at doing high-precision math. They lose a lot more efficiency implementing high-precision math than CPUs do. And GPUs are also worse at doing parallel calculations that end up following different paths, which inevitably happens when one pixel diverges before another.
My back-of-the-envelope estimates show that GPUs are not worth it for this use-case. I will change my mind when I see a GPU-based deep zoom fractal program.
Yes, but we have a lot more experience and existing code for solving this on more monolithic systems, whereas the massively parallel architecture of a GPU stops having so many advantages when you have heavy dependencies between operations on different "cores" (e.g. needing to compose arbitrary-precision math out of smaller operations), and thereby end up needing to synchronize rather than letting the threads compute in parallel.
The more interesting zooms magnify something like 10^256 times.
Fractals in the browser, in WebGL, in real time.[1] Pan and zoom around. Much fun.
Absolutely. And it's not obvious, but you can move around with WSAD keys, and QE for up/down.
It would be nice to make rendered animations in this, I don't think that's a feature of the web app. Maybe there's some other way to make animations? Would make a great background for an alien ship flying through an alien cityscape.
Ever since I've discovered 3D fractals, 2D ones simply don't cut it for me anymore.
Unfortunately they are much harder to calculate.
It's funny, I always found fractal zooms to be deeply unsatisfying. Although I know it won't happen, I keep waiting for some kind of resolution or goal. In a philosophical way, I think I have a bit of the same feeling towards life itself.. :-)
Yeah I always get the same feeling too. Traditional mandelbrot/julia whatever fractals are nice, but really boring IMO.
What's with the all the software and even file formats not supporting 4K? I mean yes it's a very uncommon resolution, but why have the number of possible resolutions fixed at all?
An excellent question. I was surprised to realized that all three video editing programs had hard-coded limits. Odd.
If you plan to watch most of your movies in 4K, you probably should wait about 10 years before buying a new TV... the movie industry doesn't adapt very quickly and cable compresses everything so much that you can't even get true 1080 even if they say that they have HD
Really, for video, 1080p is absolutely fine, if the video is not over-compressed. Even around 20mbps, 4k won't look better than 1080p, for full-motion full-color video content.
Typical movie theaters use 4k today, and 2k (very close to 1080p) less than 10 years ago. For their huge screens. Of course the bitrate is very high, "up to 250 Mbit/s" (https://en.wikipedia.org/wiki/Digital_cinema#Technology_and_...)
For small text and fine lines such as used in a close-up computer monitor, 4k+ can be very beneficial. But for video, it's marketing, and a costly waste.
One good example is that most Blu-ray movie discs are just DVDs converted to take more space (quality was not increased)
I have rented lots of Blu-rays and never found one that was upscaled from DVD to 1080p. Can you provide more details please since I am having a hard time believing that's true.
I did a quick Google search and found this article [1] ... I recall seeing a website that was listing Blu-ray titles with true-1080p but I can't find it right now. Cable does something similar by highly compressing HD content.
1. http://conversation.which.co.uk/technology/many-blu-rays-no-...
Which ones? I can't remember ever coming across one.
Why wait? Sure, some content will be overly compressed, but there is great 4K content available now:
1) Most digital photos are 4K - a 4K TV is ideal for viewing them. 2) Youtube videos 3) This video 4) Other sources of 4K video that are coming online right now.
Sure, you might not get 100% of the benefit of your 4K TV for ten years, but that doesn't mean it's not worthwhile.
In my case I had a terrible old TV, so upgrading was a no-brainer.
FWIW: The new Ultra HD Blu-Ray Disc format which supports 4K, HDR, and Dolby Atmos/DTS:X will launch soon (if you can still tolerate an optical medium). Watch for the new "Ultra HD Premium" logo on compatible devices.
Most of the content I watch from Netflix is 4K these days.