Particle Characters

Creators: Alexander Bruce
Engine: Unreal Tournament 2004
Modification: UT2K4 Player Component (eventual Mutator planned)

Last Update: 5th August 2007
Current Status: Working. More modular.
Further Development: Further modularity. More particle systems. Mutator compatibility.
Download: Not yet available

Description: Breaking down the characters you know...

Page 1 - Demonstration - Particle Characters in action (3.9MB)

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Purpose - Where did this idea start?

Pour a glass of water over the edge of a bench and see what happens. Chances are you'll wonder why you listened to me telling you to do that, as you'd have water all over your floor. Now, find a game with a character that can turn into liquid and run them near the edge of a platform, just to see what happens. If you're playing a game that has elemental characters like anything I've seen, chances are you've just got a character that's supposedly made of liquid sitting happily on the edge of a platform, that won't actually fall until you're completely over the edge.

Now, obviously there's nothing wrong with the games that have implemented things this way, as I can say that Dewy's Adventure pictured above looks innovative and fun. I also understand the repercussions for breakable characters from a games design perspective. But at the same time I'm still curious as to how you would play a game where you didn't have a character that was completely bound together. I've seen such characters in movies, such as the T-1000 and Sandman, but not in games.

Before someone leaps up and emails me examples of such characters in games, and by all means feel free to do so as I'd be interested, I wanted to try and implement something like this in a game, out of curiosity. I also didn't want one solution for water, another solution for ice, and another solution for gas, to give examples. I wanted to work out a way of doing it all with the same system, but different logic.

Working Systems - Particles, Morphable models and Boids

When deciding how I was going to do this there were a couple of considerations that I had to take on board. I'd never made a particle system, and I didn't have a clue how to get a single mesh to morph into different shapes. Working with a particle setup seemed like it would be easier to learn, as a mass of individual particles would still give the impression of being an object once all together. The morphable model, however, starts as a single object and then has to break apart, which I wasn't too excited about having to deal with.

Unreal already had particle systems within it, though I didn't end up using what was there because I wanted something more controllable, given that I was dealing with characters. I didn't mind if the final output looked a bit random, but I needed elements that I could predict. What I ended up with was actually more along the lines of boids, which I discovered a couple of weeks later. I'd already logically implemented some of the same steering behaviours as Craig Reynolds did with his systems, but his findings were still good to draw from while I continued working.

Essentially, I ended up with a whole lot of individual objects that would work together to give the same basic functionality as the systems I was modeling. The examples I can demonstrate here are both from the same system, but implemented differently as Liquid and Mist. These are the same systems that can be seen in Metamorphosis, as the game was a first attempt at bringing this all together in an unconventional manner.