Fire! Fire!

On Khan Academy a few days ago, a user asked for help. He said I was known for my animations, and that he needed fire for a game. A couple of days later, I tried writing a fire system. A couple of hours after that, I was done.

The result: a program that many people enjoyed. In only 20 hours, 46 users had voted it up. It has been 4 days since I wrote the program, and it now has at least 97 up-votes.

To create the fire, I used a particle system of a lot of transparent ellipses, a good bit of math, and Perlin noise. I added the wind yesterday, using Perlin noise to make transitions smoother. The program doesn't interact with the user; it's only supposed to look cool.

Sparking Ball

Here's a program I wrote about a week ago, for the graphics. It isn't a game, and it isn't a tool; it just looks cool. At least, I hope it does.

UPDATE: I modified the program so you can click for another ball.

If a little green guy pops up and complains about something, click restart.

Jelly Ball

A month or two after I wrote the Stretchy Ball program, I tried making the ball slightly transparent. The result: a clear jelly effect. I thought it looked cool, so I saved it as a separate program and named it "Lens Ball".

Soon another user on Khan Academy suggested making the ball jiggle whenever it was clicked. That sounded good, but I thought it would be more realistic if it jiggled no matter WHAT you did. I modified the program accordingly, and once I set it up to slide down the screen, the effect was complete. Here it is - just click and stretch:

Rubber Disk

Here's the Stretchy Disk program I named in my Stretchy Ball post. My dad soon figured out how to fix the shape, and then I added a couple of enhancements. As with Stretchy Ball, just click and stretch:

Stretchy Ball

Once I finished the curvy lines program, I butchered it and started working towards my original goal: to create a stretchy disk. I succeeded, but the shape of the disk when I stretched it was all wrong. After a while, I got my dad to come over and take a look at the math, and he started playing with it too, trying to figure out how to fix the shape.

At one point, he changed something wrong and got a ball instead of a disk. It looked pretty cool, so I saved it. Later I made some changes. Here's the finished result; just click and stretch: