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damarberlari commented on Show HN: I was curious about spherical helix, ended up making this visualization   visualrambling.space/movi... · Posted by u/damarberlari
Duanemclemore · 3 days ago
This is excellent. I'm always looking for good things to show my students on coordinate systems and geometry, and this joins the list. Thank you for diving down the rabbit hole and bringing this back for everyone.

If you want really great further consideration of creating geometric figures with parametric equations, Joseph Choma's book "Morphing" is an all-timer.

https://www.quercusbooks.co.uk/titles/joseph-choma/morphing/...

damarberlari · 2 days ago
oh wow, the book looks nice. thanks for the recommendation!
damarberlari commented on Show HN: I was curious about spherical helix, ended up making this visualization   visualrambling.space/movi... · Posted by u/damarberlari
mayoff · 3 days ago
You can play with the equations on 3D Desmos here: https://www.desmos.com/3d/t66etxi1y8

Interesting to note that the parametric equations of the spiral are linear in spherical coordinates. https://en.wikipedia.org/wiki/List_of_common_coordinate_tran...

damarberlari · 2 days ago
this is nice, thanks!
damarberlari commented on Show HN: I was curious about spherical helix, ended up making this visualization   visualrambling.space/movi... · Posted by u/damarberlari
hailpixel · 3 days ago
I LOVE when people geek out about the most simple mathematical things*, especially discovering the animation power of the trigonometric functions... or any of mathematics underlying modern interactive stuff. It's one thing to know what they do, it's another to understand the power of that tool.

* I wrote a similar article around making "blobs" a while back: https://www.hailpixel.com/articles/generative-art-simple-mat...

damarberlari · 2 days ago
hi, whoa that's a nice article! simple and easy to follow.

thanks for sharing! definitely an inspiration, I might use it for next project :D

damarberlari commented on Show HN: I was curious about spherical helix, ended up making this visualization   visualrambling.space/movi... · Posted by u/damarberlari
pimlottc · 3 days ago
I was wondering about the “correctness” of the z-axis movement for the spherical helix. You could pick lots of different functions, including simple linear motion (z = c * t). This would obviously affect the thickness and consistency of the “peels”.

The equation used creates a visually appealing result but I’m wondering what a good goal would be in terms of consistency in the distance between the spirals, or evenness in area divided, or something like that.

How was this particular function selected? Was it derived in some way or simply hand-selected to look pleasing?

damarberlari · 2 days ago
> You could pick lots of different functions, including simple linear motion (z = c * t)

that was also my first intuition when making this, but turned out making the z function linear won't make it a sphere.

to make a sphere, you have to configure it in a way so that it forms a circle with the other axes. In this vis, its the sin(0.02 * πt) and cos(0.02 * πt) part that do this.

someone makes an interactive version here: https://www.desmos.com/3d/t66etxi1y8 (thanks!) so you can try changing the z function for yourself.

damarberlari commented on Show HN: I was curious about spherical helix, ended up making this visualization   visualrambling.space/movi... · Posted by u/damarberlari
erikerikson · 3 days ago
Oh, you're right. Small and at the bottom. I guess I tried to scroll before my eyes got there. Thanks for pointing out my error.
damarberlari · 3 days ago
ah, yes there is an instruction at the bottom, but probably its too small.

thanks for the feedback!

damarberlari commented on Show HN: I was curious about spherical helix, ended up making this visualization   visualrambling.space/movi... · Posted by u/damarberlari
Keyframe · 3 days ago
Neat! I was curious as well after reading it and here's a quick parametric visualizer to play with what was described in the text (thanks, Claude!): https://codepen.io/CaptainKeyframe/pen/zxvWVNo
damarberlari · 3 days ago
wow, that's nice. Thanks!
damarberlari commented on Show HN: I was curious about spherical helix, ended up making this visualization   visualrambling.space/movi... · Posted by u/damarberlari
sfink · 3 days ago
Awesome visualizations.

The part that I was expecting to see but didn't: how can you move at a constant speed? For the original purpose of positioning objects along a path, it doesn't matter. But when moving, you can see it's moving much more slowly at the beginning and end (mostly determined by the radius). What if I want it to travel at a constant rate? Or even apply an easing function to the speed?

I'm sure there's some fancy mathematical trick that would just do it. If I were only more comfortable with math... my handwavy sketch would be to compute the speed function by differentiating the formulas to get dx, dy, and dz and passing them through the Pythagorean equation, then reparameterize on a t' variable using the inverse of the speed function? Maybe? I feel like I'm speaking using words I don't understand.

damarberlari · 3 days ago
thanks!

currently the path is expressed as function of (t), and it's the t that progressed at the constant speed.

so the cube will finished one loop at the same duration, and thats why it moves much slowly at the beginning and end, where distance of one loop is smaller.

I have to admit I made it that way because it's simpler to implement:D. Making it move at constant speed require some more works, but others have provided some solutions here so I think I'll try

u/damarberlari

KarmaCake day281July 9, 2025
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