Last night, I had the idea to take part of the previous fluid solver, but instead of placing the “ink” in a grid, I’d replace it with particles and have those move according to the velocity grid. It would give a stronger impression of detail.

It didn’t look all that great from a realistic point of view, but I discovered that when I added permanent trails, things started to look more interesting, even tho I was moving further and further away from my initial idea. After some more experimentation, the result is some interesting pseudo-art (”pseudo” since I’m not an artist, and never will be ).

I like how some of them turned out, but that’s coming from a guy who likes to look at pictures of strange attractors and spends too much time staring at his cigaret smoke

All of these were generated in Flash using Alchemy.

Thanks to Ralph Hauwert’s blogpost pushing a baffling >300.000 particles using Alchemy, I finally got the much needed motivation to try out Alchemy myself. To be able to get started asap, I decided to return to something I’ve done before: fluid and smoke dynamics, but with a different algorithm (see Mike West’s article on Gamedev). It took me a while to figure it out, but it’s up an running! It’s a faster algorithm, but less physically correct.

While I typically would do most of these kinds of calculations in Pixel Bender, for the examples below, I decided to try it all in C and see how far Alchemy can be pushed. The grid is bigger than before, while the framerate is steady around 20 on my machine. Ralph has suggested some improvements for the rendering step already (thx! ), so I’ll have some more experimenting to do

It was great to return to C, especially since it’s been 8 years since I’ve written my last line in that language. Quite a rush of nostalgia!

Source is included with the demos, tho it’s not the most reusable I’ve ever written

• Smoke simulation: add and move around smoke (Source)
• Milk and Ink (fluid within fluid): milk is healthy, until you add ink! (Source)

The HiRes FPS counter is done by Mr. Doob.