fractal result by accident

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41 comments, last by Bacterius 10 years, 2 months ago

I was tinkering a bit with my basic raytracing code and by accident i

received some kind of fractal pattern

[attachment=19801:ff.jpg]

does maybe someone know if it has some official name? i think i saw this already in some book or something

the code to get this is like i was counting distance from screen points (along the rays) to sphere (this distance should be about 0 to 1000) then just multiplying this by 255.9

casting to unsigned and adding it like

unsigned color_ = (red<<16) + (green<<8) + (blue);
then setting pixel :/ i do not know exactly reason of this outcome but it is funny ;\ (in mathematical way)
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Looks like normal sampling aliasing or interference patterns. As the frequency of the rings increase, they approach and pass the limit at which you sample the rings at the pixels.

Looks like normal sampling aliasing or interference patterns. As the frequency of the rings increase, they approach and pass the limit at which you sample the rings at the pixels.

may be but besides is a some specyfic fractal structure, (type of fractal) probably/maybe has some name

Zoom in on those structures and see what happens when you get closer to them. If the patterns change as you zoom in, then this is definitely just normal sampling aliasing. The fact that you only calculate a distance and transforms it into some color means that the pattern should just be circular rings around a center point, but circular patterns with too high frequency for the display produces those particular patterns. Nothing fractal at all about it.

...probably/maybe has some name.


It does: Moiré

Zoom in on those structures and see what happens when you get closer to them. If the patterns change as you zoom in, then this is definitely just normal sampling aliasing. The fact that you only calculate a distance and transforms it into some color means that the pattern should just be circular rings around a center point, but circular patterns with too high frequency for the display produces those particular patterns. Nothing fractal at all about it.

I cannot agree this is not a fractal, iMO this is a well defined fractal.

I think this coloring is stable, it is you probably can paint a real wooden

ball this way - this is probably effect of colouring some geometrical surface based on distance to point with cyclic palette - you will get stripes here, if distance would be counted from only one point you will

probbly get centric circles on a ball, but this distance is counted not

from one point but from each screen pixel so it results in such strange fractal (this is what i think i am not sure)

zooming the ball I think will not change the effects with covering spray

(just zooming it) but probably with rising the spatial frequenzy of palette wil uncover infinite complexity of the rings... that i suspect

Why "I think" and "I suspect" when you can try to verify your claims and be completely confident instead? Zoom in on some part of the image showing a fractal behavior. If it is indeed a fractal pattern, the pattern should remain stable as you zoom in and recalculate the region at a higher resolution.

Here's a link for you describing the effect you're getting: clicky. There are some examples near the end showing pretty much exactly your results.

You may also be able view the effect, including zooming, on the resolution chart on page 4 in the PDF. The small part in the middle with some circular patterns shows the exact same effect on my screen when zooming out to view the page as a whole. This is because the resolution of my screen is too small to capture the frequencies of the circles. As I zoom in on that part of the figure, the circles become clear and the aliasing effect disappear when the circles are rendered at a higher and higher resolution.

Clearly an aliasing effect and nothing fractal about it.

Clearly an aliasing effect and nothing fractal about it.

If you say so ;\ (yawn)

You asked about an effect that was unknown to you and I gave an answer about an effect that is known to me. You don't have to take my word for it, but I did give you experiments you can perform to either enforce or refute my answer. I have at least provided examples to back my answer up and mentioned experiments you can do to see for yourself. It is not about just believing in my word at that point.

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