Experimental Gameplay Workshop Talk
This talk was given on March 22, 2006, as part of the Experimental Gameplay Workshop, which is held every year at the Game Developer's Conference. The talk centers around the inspiration and theory behind Ocular Ink's painting interface. John gave the speech, and Justin worked the demonstrations and slides. Below you'll find an approximation of what was said, as well as a selection of the slides that were shown.
Script Slides
Hi. My name is John Edwards, this is Justin Kim, and we're from Pistachio Productions. We're going to be talking about our new game, Ocular Ink, an overhead adventure set billions of years in a future where humanity has de-evolved into giant body parts. You play the role of a young eyeball who must save his village from the evil eye-pirate, Patches Deadlights. Being a giant anthropomorphic eyeball, you're only weapon in this fight is your trusty paintbrush. The paintbrush is the player's primary method of interacting with the game. You move it around with the mouse, and you hold down the left mouse button to paint magical symbols on the ground.
When the game begins, the village elder teaches you your first spell, which is simply called the "flick".
The way the flick works is you draw a line from an object in the direction you want to flick it. The length of the line controls the speed at which the object will be flicked. It's a simple concept, but with our physics system which registers impact damage, it's actually a pretty versatile weapon.
Now, after you learn the flick, you return to your village to find that Patches has ransacked it and fled to the top of Mt. Oculus, on which is built a giant laser pointed straight at your village. Patches has sealed off the mountain pass with three magic orbs, and dispersed them amongst his lieutenants, who hide them away in the far corners of the land. The first lieutenant, Kenki, the "samur-eye", has run off to the Forest of Death. Justin will use developer powers to summon Kenki and battle him. Kenki hurls bursting appendix bombs and dashes at you with a Chi attack. Notice how Justin is using the flick and the physics system to lay the hurt on Kenki.
Bosses, like in other games, offer a tougher challenge. Defeating them is no walk in the park or a simple game of online bingo. However when you do defeat a boss, you take the orb he was guarding, in this case the "Orb of the Forest." You add the power of the orb to your paint supply, and gain a new spell. The spell you get from Kenki is the scribble explosion. You just scribble on the ground and it creates an explosion. The larger the scribble the larger the explosion. However, the denser the scribble the more damage the explosion does, so there's a trade off between size and power.
The next lieutenant is Whipstone McGee, famed "arch-eye-ologist", and in the game you must chase him through the Ruin of Pain. Instead of doing another boss fight, Justin will use developer powers to summon the orb, which unlocks the spiral/vortex spell. This spell comes in two flavors. When you draw an inward spiral, it sucks everything in and mashes it together like a blender. The outward spiral creates an updraft, allowing you to fling stuff out of the way, or even make small jumps. The larger the spiral drawing, the more area it covers. The more rings in the spiral, the more powerful the effect.
The last of Patch's minions is Phemus, the "eye-clops", who lives on the Island of Evil. His orb gives you the ring/laser spell. You draw a circle and shoot a laser from your pupil to the center of the circle. The larger the circle, the stronger the beam, but the harder it is to aim.
These are the four basic spells in Ocular Ink, flick, explosion, vortex and ring laser. They are all invoked through the gestural interface. Traditional gestural interfaces have you draw random symbols to triggers predefined effects. Essentially, the symbols act like buttons. Buttons that take five seconds to press and, more often than not, don't work because the interpreter fails to recognize them. With Ocular Ink, we tried to make our gestural system different in two ways:
First, we exploited gestures' potential to convey a lot of information. A button can be up or down, but with gestures, you can tap into characteristics like size, position, orientation, quality, drawing speed, etc. This fact makes them potentially much more efficient and expressive than button presses. In Ocular Ink, we tried to always monitor a number of attributes of the symbols. So even though it takes longer to draw a flick line than it does to press a button, the user's time is well spent, because the position, direction and length all factor into the flick's effect on the game world. All the spells are like this.
However, this expressive power of gestures is useless if the player doesn't understand how they work. The other thing we tried to do differently with our gesture system is make it intuitive. Onomatopoeia describes the use of words that sound like their meanings, such as buzz or murmur. For Ocular Ink, we tried to pick symbols that "drew" like their meanings. That is, we wanted to make the act of drawing evoke in the player's mind the kind of action the symbol would trigger in the game world.
For example, with the flick, you actually flick your wrist in the direction and with the speed you want the object to be flicked in the game.
At this point, I want to talk about why we came up with Ocular Ink's control scheme. A year ago, we were here at the GDC as part of the IGF Student Showcase with a game called Mutton Mayhem. Mutton Mayhem is a multiplayer game about competition over limited resources, and sheep. Before the GDC, we'd taken it to some LAN parties, where it was pretty well received by the hardcore gamers, there. However, at the IGF, which seems to attract a fair amount of casual gamers, we had a hard time getting people involved with the game.
Sure, Mutton Mayhem is the type of game that encourages you to wait for sheep to come out of the ground, slaughter them, transform into a necromancer, raise their corpses and herd the zombie sheep back to barns for points, but I don't think that was the problem. I think the problem was that the controls for doing all that stuff are pretty intimidating. People would slaughter when they should be herding, and raise when they should be slaughtering. The experience at the IGF, and the LAN party's before hand, led to the following theory, which, in turn led to us designing Ocular Ink's control scheme the way we did.

The theory goes like this: Input schemes can be evaluated primarily based on two separate factors: power and intuitiveness. Power describes how expressive the control scheme is, as well as how quickly action can be input. Intuitiveness describes how easy the scheme is to pick up. Mutton Mayhem would probably be somewhere up here.
That's also about where games like Soul Caliber and Street Fighter would go. All sorts of crazy martial arts moves arbitrarily mapped to buttons on a controller. The WASD/mouse-look input system for first person shooters would probably be a bit over here. It's still a pretty powerful input system, but the close mapping between moving the mouse and moving the avatar's head, and the similarity between pressing a mouse button and pulling a trigger makes it more intuitive than the fighter game controls. Hack and slash RPGs, like Diablo, would probably go over here. These interfaces are pretty intuitive, point and click, they just use one button, but their power starts to get limited. You can walk, you can hack, and you can slash. Further down we have casual games. You can pick the controls up instantly, but all you can do is move around colored blocks. Over in the bottom left would be things like the DOS command line interface ... or the Ocular Ink level editor.
Now for some complete generalizations.
The quality of a given input system depends on where you view it from. If you're an elite action gamer, all you care about is how much power the control scheme will eventually let you wield, even if it takes a while to learn.
In fact, obscurity can sometimes become a matter of pride, for these people.
If you're a casual gamer, or a non-gamer, even, you've probably never heard of WASD, and you don't particularly want to. All that matters is that you can jump right in, have a little fun, and jump out.
That's why with Ocular Ink we tried to go right up the middle. We consider ourselves fairly elite gamers, so we wanted a control scheme with power, but we didn't want a repeat of last year's IGF, where the control scheme was so unapproachable that no one could actually discover the meat of the game. Well, given that we're a small team, and dealing with some fairly experimental concepts, I'd say we made it about this far.
Luckily, the graph has a third axis: time. As time passes, technology improves, allowing for more powerful control schemes. Time also allows people to get used to existing control schemes, transforming the intimidating into the intuitive. With the rise of touch screens and position aware controllers, I think this is especially true for gestural interfaces. Gestural interfaces that exploit the richness of data that comes with drawing symbols, and use physical onomatopoeia to intuitively link the symbols with their in-game actions have a lot of potential.
Check out Ocular Ink at the IGF pavilion (we're in the Student Showcase again, this year), or on the web at www.pistachioproductions.com. Thank you.