galaxy numerical simulation in freebasic

[chung]

galaxie chung is a galaxy numerical simulation trial i have written in fast compiled freebasic for calculation and openGL for displaying.

=> http://chungswebsite.blogspot.fr/search ... axie_chung

https://www.youtube.com/watch?v=0nGqHLgxTJk

[D.J.Peters]

good job
do you use any paper for move() and gravity() ?

Joshy

[chung]

no paper i think, its just an old program i made when i was studient , but on that time the computers were not enough powerfull (the most powerfull was the Cray 1 , which was unaccessible to me). Now i have the power of a Cray 1 with my netbook and i have freebasic and opengl , so it is worth running it.

(25/05/2014) load, save, replay added

[TESLACOIL]

Fascinating stuff.

Galaxies shed energy over time in the form of light and cosmic rays. They also heat up due to the hidden energy that's released via fusion of light elements. It would be interesting to see how such factors shape the evolution. Also the speed of light/gravity will have an effect.


Crash of the Titans: Milky Way and Andromeda Galaxy
https://www.youtube.com/watch?v=2WEI8WBJkKk

[KlausPeterVDL]

http://play.infiniverse-game.com/

go there, click, then press backspace for a mindblowing javascript version of this very thing.
save the site locally, comment out "this.energy -= amount;" in ship.js and reload to explore.
his galaxy code is in. uh... galaxy.js clean oop, mindblowing and simple algos. love it

just thought you might enjoy working his noise code into your viewer (and library of general awesomeness)

[h4tt3n]

This is great work Chung, I really love it. Despite having worked with gravity simulators and grid based physics before, I am a bit unsure how this works exactly. Would you care to describe what's going on in the simulator?

Cheers,
Mike

[chung]

well , its more a computational cooking than a maths theory , heres what is done :
it has to run on a small netbook so cpu speed is the priority
the galaxy is considered as a 2D gas of stars.
at each iteration, each grid square of stars gas is applied a speed displacement and a speed gravity acceleration.
the near gravity (less than 1 square distant) is not taken in account as it would bring instability and at this scale the gas property and the numerical approximation are supposed to be preponderants.
after displacement each gas square is redistributed in the grid with the principe of mass and impulse conservation in the four nearest grid squares.
works with 70..100 squares grid fast enough.