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I’ll shorten this one even more than the last one, but that’s okay, because the subject of this week’s Dev Diary isn’t too complex of a subject. I just wanted to briefly touch on the subject of replaceable components in animation as I was starting to work on some for our Touch of Death characters. Peeking into my animation workspace would unveil a nightmarish assortment of disembodied heads and limbs, and I figured I may as well explain why. It seems someone had beaten me to the punch with this when talking about Yogi Bear’s collar just a few weeks ago, but it bears stating not just as an animation trick, but as an element of game design.

When discussing Yogi Bear, one of the points brought up was that for a Television Cartoon you needed quicker turn-around times than the comparatively big budget and slowly produced Looney Tunes cartoons that were designed, originally, as pre-movie entertainment in theatres.

It’s called Limited Animation in a technical sense, and the concept is to re-use content or find tricks to avoid drawing complex things at all, such as hiding foot or mouth movement. In the above example, you can see three characters with collars of some sort. Each of these allows you to create a dividing line between the body and the head. The head, in this situation, could easily be kept as a seperate cel and simply replaced on top of the body before each frame was ‘snapped’ by the camera.

As an additional bit of trivia, notice how all these faces are essentially at a 3/4ths turn to the camera? It makes faces easy to see but also very easy to replace on the torso, lets you mirror the torso with limited turns, and lets you even keep the head stationary and simply replace the mouths with a few lines!

This was clever because it used the hardware at hand to do the work for you. For people who’ve never operated a traditional animation stand, you generally have a big Background to the action, often set up on a scrollable piece of film, on top of which you place animation frames, IE, animation cels. Each cel is essentially a layer of clear plastic with elements drawn on top of it with a camera set up to photograph each combination of cels and backgrounds as a frame in what eventually becomes a complete animation. This was hard work!

The stands have slots fit on them, the Peg Bar, with corresponding holes cut into the cels. This is called the register. By keeping things “in register,” you can make sure that all the cels stay positioned relative to each other.  Add in the ability to independently slide the layers and now you have a workspace as advanced as Photoshop’s digital layering. This lets you create complex animations without needing to draw more than just parts of a character at once and layering cels on top of each other.

One of the lamest forms of this is simple Mouth Replacement animation, where you not only don’t bother to match mouth movements, but where a character stays perfectly still while separate layers of mouth animations are flipped between atop.

Sometimes it’s done for a purely aesthetic effect though, and to great success. A famous example among animators is “The Dover Boys,” which used a variety of limited animation principles and especially the use of “smear” or “wipe”  frames. These are frames designed to fake motion blurs and—hey wait a minute, I know where I’ve seen that example!

In video games, you do a nearly identical procedure in code—at least that’s how Adam describes it to me. So if you want to create a character with 100 different weapons or punching techniques or something, the easiest way to do it is to actually animate the body in such a way that the hands or the swords or whatever can change on the fly.

For Touch of Death, this is how we’re going to squeeze so many unique looking frames into such a small space. The main character’s striking hand will actually be snipped off and placed on top during attacks as a separate ‘layer’ to be drawn. The ninjas, with their variable weapons and equipment, will be done the same way.

This means you’ll want to think ahead when you’re designing your characters. If they’re performing attacks that make it hard to drop-and-replace a weapon into their hands, you might be making yourself a headache if you want to show a variety of hardware. This is a lot easier in 3D games actually, since a character like Heavy Weapons Guy isn’t actually welded to his gun, it’s a separate model and you can pretty easily swap in new ones and just tweak some animations to avoid clipping.

The How and Why

How:  Simply make your game with swappable parts in mind and re-use when you can. Find opportunities for adding variety, and then make it so you can easily change bits and pieces up to simulate it.

Why: It’s faster, easier, and smaller to do it this way. You can run the game faster, give the player more stuff to look at, and generally improve the experience all around. Even though it’s called “limited” animation, it really does free you up to do a lot of things in a very creative way.

Spacelab Signing Out

It’s a simple trick, but it lets you do some pretty amazing things when you apply it properly. It’ll save you a lot of time, but the real kicker is the amount of space you can save by not needing to create unique frames. It will also let you add more variety to the game in a simple way, and that makes for a much richer experience.  Talk about a win win. By the way, go watch The Dover Boys in action now that you can appreciate just how much work this was!