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Maybe I should do a small #introduction

Hello everyone! I'm Ron(i) and go by Roninkoi in most places. As a kid I started off making games for competitions such as #LDJAM, but these days I'm more into the technical side of things. Graphics programming and #creativecoding is my main interest, especially #demoscene and #retrocomputing. IRL I'm a computational #physics grad student working as a part-time code monkey

$$

\frac{\partial^2}{\partial x^2} f(x, y) + \frac{\partial^2}{\partial y^2} f(x, y) = g(x, y)

$$

in parallel using OpenMPI: https://github.com/Roninkoi/ParPS

The problem is parallelized using domain decomposition and each piece solved using successive over-relaxation.This can be run on a single PC or a multi-node compute cluster #hpc

Some hexagonal #turingdrawings from my #cellularautomata simulator-thingy I'm working on.

Up next: anything that doesn't involve clicking restart 500 times to discover those that aren't a straight line.

\begin{align}

p_{n+1} = p_n + K \sin \theta_n, \\

\theta_{n+1} = \theta_n + p_{n+1},

\end{align}

with varying \(K\). It's pretty hypnotic https://www.shadertoy.com/view/WdjcW3

As it turns out, there is a better approach using Clenshaw's algorithm! A review of different methods is given in arXiv:1410.1748 [physics.chem-ph]. Now I could get up to high values of \(\ell\) and \(m\) without everything blowing up! From the ALPs we can then simply obtain the SHs as

\[

Y_\ell^m(\theta, \phi) = \sqrt{\frac{(2 \ell + 1) (\ell - m)!}{4\pi (\ell + m)!}} P_\ell^m (\cos \theta) e^{i m \phi}.

\]

The final code can be viewed at https://www.shadertoy.com/view/3dKGWG, which borrows from iq's shader

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\[

P_\ell^m(x) = \frac{1}{\Gamma(1-m)} \frac{(1+z)^{m/2}}{(1-z)^{m/2}} {_2F_1}\left( -n, n + 1, 1-m, \frac{1-x}{2} \right).

\]

This requires computing a series consisting of many factorials, which is slow and results in precision problems

Here’s my #intro

I’m a mechanical engineer by trade, and designed many components for various Macs over the last decade. I recently quit my job in order to return to school and obtain a PhD in math.

I find geometry fascinating and make Rubik’s-cube-like puzzles as a hobby. Last year when trying to answer some open questions regarding these puzzles, I was introduced to #math concepts I had never been exposed to. During that exploration, I simply fell in love and decided to dive in head first.

Here we see Hickson Compact Group 88, a quartet of galaxies that are surprisingly chilled out given how crowded their environment has become!

Usually these galaxy interactions are stressful events, and here we see some evidence of galaxy evolution: the two northern galaxies are flinging away some of their older (redder) stars. But the two southern galaxies seem to be quite undisturbed!

Oh man oh man oh man oh man -- the Ingenuity Helicopter on #Mars swung over and took a view of the backshell and parachute used to land Perseverance on Mars! It is so cool what we can get up to when we have a little drone accompanying our rovers. #JPL #Mars #Astronomy #Perseverance #Space #Science

Raw image: https://mars.nasa.gov/mars2020/multimedia/raw-images/HSF_0414_0703689952_044ECM_N0260001HELI00005_000085J

Once again I've participated in the Paint Over Fast Competition at Revision 2022. Skullship Robo Repair (inspired by a chaos picture) was created within less than 24 h including sleep and breaks. It won 2nd place. https://www.deviantart.com/sylviaritter/art/Skullship-Robo-Repair-913428468 #art #mastoart #paintover #revision #demoscene

I've been working on a new series of 3D fractal shapes intended for 3D printing and tabletop gaming. These are shapes that remind me of natural (or alien) terrain.

I find and extract the 3D meshes using Mandelbulb 3D and process them in ZBrush.

Most of these I've already test-printed, but I still need decent photos of the results.

- Website
- https://www.roninkoi.net

- https://twitter.com/Roninkoi

- Github
- https://github.com/Roninkoi

I make games sometimes! Graphics programming enthusiast. Physics grad student. Finnish dragon 🐲🇫🇮🐉

Joined Apr 2022