Wednesday, October 21, 2020

Computer Simulations in Physics, edition 2

Let me announce this that, together with my leading editor, we are finishing work on the second edition of my simulations book:

"Computer Simulations in Physics, edition 2", Maciej Matyka
Helion (polish), [368 pages]
Topics: numerical methods, spring mass systems, soft bodies, cloth dynamics, wave equation, fluids, Marker-and-cell mehtod, Lattice Boltzmann model and real-time quantum physics.

Codes in C++/HTML5 are now freely available.

Boook release date December 2020.

Friday, May 22, 2020

SODA 2 - Looking for betatesters

Hi, I'm looking for betatesters for the new version of "new soda" with .xml import/export, static points, 0 length springs etc. If you like to become one, pls email me at

Thursday, April 2, 2020

Modelowanie 1: Zlepki DLA (Diffusion Limited Aggregation)

Modelowanie 1
DLA jest modelem, który jest bardzo znany w fizyce komputerowej i pochodzi z pracy z Phys. Rev. Lett. (najbardziej prestiżowe czasopismo fizyczne), artykuł ma naprawdę dużo cytowań jak na fizykę, a "chwycił" chyba głównie ze względu na prostotę i niesamowite wyniki jakie uzyskuje się tak prostym opisem.
Ogólnie wędrowniczek chodzi losowo po układzie i 'przylepia' do zarodka. Miejsce przylepienia staje się zarodkiem. Możliwości są tu nieograniczone, można to zrobić szybko (algorytm), w 3D (wizualizacja), można nawet ciekawe rzeczy policzyć, zrobić film z tworzenia się zlepka itd.

Tuesday, January 14, 2020


As you know I've decided to.. port what I remember from the original Soda Constructor to the new world of html JS apps. What I found the most frustrating was to find a proper name for it. Also, I was not sure what direction to take, I did many versions, spent many hours on going back and forth adding and cutting down the app to it's basic versions. I even found a few models on the internet and wrote simple importer... which worked. There were two users (cheers!) who wrote to me and gave some feedback.. The point I am in now is that I have 3 or 4 versions available online, all with different names, I even wrote part of a chapter to my simulations book (2nd edition) where I describe how to write such simulation which generated another instance of the app. I wrote blog post which became quite popular and people find the app.. So.. If you find some time to test all the versions, want to discover it again, give me some feedback, point me out which version is the best / the most useless, give me some directions, comments, ideas how to make it / remake it so that 5th version will be really useful and enjoyable, please find yourself welcome to test the following links:

Wednesday, October 23, 2019

My remake of Soda Constructor got "Load XML"

Are you old fanboy of Soda Constructor? This is experimental, not fully working and highly risky option but you may now try to load your old Soda Constructor XML models into my JS version. I tried a few and they more or less work. Enjoy!
ps. I've added sound too ;)

 play it here

Brak dostępnego opisu zdjęcia.

Wednesday, April 24, 2019

Diffusion Limited Aggregation

Particles suspended in fluids may diffuse and exhibit random-like motion.
If we stop their motion as they get close to other stopped particles they will create fractal-shaped figures known as Diffusion Limited Aggregates. So the algorithm of the simulation is simply:

1. assign the first "stopped" particle (i. e. in the origin of the system)
2. choose random positions of N particles (the best would be far from the origin)
3. for each particle:
 - randomly choose direction of motion
 - move the particle
 - if any of its neighbours is "stopped" -> stop it.
4. continue the loop 3.

This physical mechanism is simple yet brings beautiful results. Also, it is really simple to code and used i.e. during our classes to teach programming as well as simple modelling. Examples of such figures are below. They are all done with a simple full-screen HTML app I wrote to visualize DLA for purpose of my lectures. Enjoy, it's free.