Wednesday, March 28, 2012

Love Is a Many-Headed Thing, Part IV

What would a one-headed hydra look like? Considering that hydras are always depicted in art as having many heads, the idea of a one-headed hydra may sound silly. Let us not forget, however, that when Heracles first encountered the hydra, it started out with only one head. The appearance of that head will determine how the rest will look.

I searched the Internet for pictures of hydras, and I found various depictions of it with fins, barbels (appendages like the “whiskers” of catfish), horns, beaks, and even greyhound ears. Why would a hydra have one or more such features? To be sure, reptiles have been known to have fins (sea snakes, ichthyosaurs), horns (triceratops, horned lizards), and beaks (turtles), although I have yet to hear of reptiles with barbels or external ears. Nevertheless, there has to be some credible use for any trait. Unless the hydra spends all its time in waters deep enough for its huge body to swim in, it would have no need for fins or barbels. Horns are good defensive weaponry, but, like ears, they can make locomotion for a legless creature difficult. Besides, horns are clearly inferior to poison fangs. Beaks are good for cutting up food to a manageable size, but they are completely unnecessary to a creature that can open its mouth very wide.

As I mentioned in a previous blog post, form follows function. The hydra’s features must serve to help its species survive in its natural habitat. That means they must help the creature eat, keep from being eaten, and reproduce. One cannot simply slap miscellaneous body parts on the hydra just to make it look freaky. Otherwise, one risks having people scoff at the preposterousness of the creature.

Hydra Behavior 101

If I were to give some semblance of verisimilitude to the mythical hydra, I would make it behave like any other venomous serpent. The way I see it, the hydra is a reclusive, non-confrontational creature whose coloration allows it to blend in its swampy environs. When threatened, the hydra raises its heads and splays them out to make itself look bigger. It issues a chorus of threatening hisses and bares its fangs. It weaves its heads about, ready to strike. Unless the creature threatening it is something the hydra will want to eat, the hydra will prefer to conserve its relatively weak venom until it is obvious that the creature won’t leave the hydra alone.

The hydra does not rely on its eyes or hearing to sense other creatures. Vibrations in the water or on the ground serve to alert the hydra to movement. It flicks its forked tongues out to smell the presence of predators, prey, or potential mates. It also uses two heat-detecting pits on each of its faces to lock on to its target. For all intents and purposes, the hydra is immune to blindness and can easily detect hidden or invisible creatures. Spells of etherealness can make one undetectable to the hydra.

In its natural environment, the hydra can hide as if it were a Rogue of a level equivalent to its hit dice. Nevertheless, the hydra suffers penalties to Hiding because of its huge size as well as the difficulty in getting its many heads to coordinate actions. A hydra can lie very still for extended periods of time. In fact, once it picks a spot in which to lie in wait, the hydra is unlikely to move. Without a predator or prey to react to, it is difficult for the hydra to get all its heads to agree on where to go.

The hydra feeds on whatever it can get its maws on – fish, deer, alligators, and teenage lovers who think that swamps are the perfect place to make babies. (No, actually, a hydra isn’t in the habit of eating humans because they have a nasty tendency to form hunting packs and avenge their dead.) The hydra prefers to strike while hidden because it cannot hope to outrun most of its prey. Even without the advantage of surprise, its initial appearance may shock and awe creatures into momentary paralysis if they fail their Will save.

For a hydra, having many heads is both a blessing and a curse. A single bite from a hydra is not particularly lethal to a medium-sized creature, probably because it has to supply so many heads with poison. The combined attacks of all its heads, however, are enough to kill an adult hippo. When it has delivered sufficient venom to make its target too weak to run away or put up a good fight, the hydra withdraws and waits for its prey to die. Only then will the hydra make a grab for its food, initiating a struggle with itself. Like all snakes, the hydra swallows its food whole. Its many heads may wrestle with each other for hours over the privilege to eat. Fortunately, a hydra can go without eating for a year or two. It can certainly afford to wait a few hours more to sate its hunger.

Much has been said about the hydra’s alleged ability to grow two heads when one is cut off. Personal experience from a brave and stalwart adventurer (ahem) belies this claim. Most likely, this is a tall tale spread by villagers to keep their teenage children from trying to make babies in the swamps. What has been verified is that decapitating a single head will not kill the hydra. It will continue to fight for as long as it has heads. While the hydra can eventually heal from the loss of a few heads, they will never grow back. Our brave and stalwart adventurer (ahem) was fortunate in having fought a hydra with only two heads remaining, as well as a number of stumps where other heads used to be. The bodies of fallen adventurers nearby yielded much loot and made the venom sickness that lasted for a few hours worthwhile.

Portrait of a One-Headed Hydra

It is clear from the above write-up that I intend to make a hydra with a fixed number of heads. I’ve already explained in a previous blog post my concerns with the whole spiel about growing new heads. Nevertheless, once I have a one-headed hydra, creating a multi-headed one will be relatively easy.

My write-up also makes it clear that everything a hydra needs to survive in the wilds is already found in venomous snakes such as the pit viper. Anything extra will simply weigh it down. I want to make the hydra approximately as long as an anaconda, although pictures on ancient Greek pottery of Heracles fighting the hydra seem to indicate that the hydra was smaller than that. It certainly won’t be as large as the one in Jason and the Argonauts. (That’s right, Hollywood. It was Heracles who fought the hydra, not Jason.)

Having decided on the hydra’s appearance, I took this opportunity to revisit the snake I built earlier. Looking closely at my reference pictures, I realized that I got the mouth wrong. A snake’s tongue is supposed to retract in a sheath at the bottom of the snake’s mouth. My original mesh had no such sheath. Much as I hated to do it, I had to work on the snake’s mouth all over again. I also decided to retopologize the rest of the head because it had too many triangles instead of quads. I rescaled the body to make it wider in the middle and to make the tail look less like a stabbing weapon. Naturally, all this meant re-doing the UV map, along with the high-poly sculpt in ZBrush. The low and high poly models can be seen below.

It took me over a week to decide on the one-headed hydra’s appearance and to refine its basic shape. Since then, I’ve been trying to find a good way to texture it. For reasons that I will explain in my next blog post, this issue has been especially problematic. Stay tuned.

Wednesday, March 7, 2012

Love Is a Many-Headed Thing, Part III

A hydra is not an easy thing to model. Each head should be sculpted symmetrically and animated individually. Be that as it may, a hydra is basically a fancy snake with more heads than are considered healthy. If I could sculpt one snake and embellish it to look like a one-headed hydra, it would be a simple matter to replicate the head and neck and attach each clone to the body.

Regarding the position of the heads, I’m not inclined to follow the hydra model in Jason and the Argonauts, where one row of heads is on top of a second row. Apart from looking kind of messy, the heads that are in front will always have a clear advantage over the ones at the rear when it comes to grabbing food.

Instead, I’d like to position all the heads in a single row like the fingers of a hand. It makes more sense to have each set of vertebrae fused side by side, the way it happens among conjoined twin serpents. This design is based on some amazing pictures of snakes with as many as five or ten heads that I found on the Internet.

With that plan in mind, I figured it would be a cinch to make a snake model. After all, it is the easiest vertebrate to draw, almost as easy to draw as a worm. A snake has an oval head devoid of any nose, ears, or hair that would only serve to complicate it. Attached to its little head is nothing more than an inordinately long tail. Even a child can draw it, so sculpting it ought to be a simple matter to me.

I mean, look at some of the things that I’ve sculpted in the past.

Surely a snake would be child’s play for me, right? Right?

Wrong. Below is my first attempt at modeling a snake. Eat your heart out, Michaelangelo.

Obviously, the body wasn’t quite right. I decided to take a more careful look at my reference pictures. I found that while the neck of a snake is narrower than its head, its body widens considerably towards the middle before tapering down to the tip of its tail. Also, the sides of a snake can be surprisingly flat, rather like a very long and rubbery box.

Armed with this new realization, I made another attempt to sculpt a snake.

What went wrong, I wondered. Why do I have no problem drawing and sculpting complex human bodies but get stuck trying to sculpt a simple snake? The answer wasn’t as surprising as one might think. I have had many years of experience drawing people but have had virtually no experience drawing legless reptiles. The subtle shape of serpents was lost on me.

Yes, a snake’s body can appear to be relatively flat like a box, but it doesn’t have sharp corners outside of its mouth. I needed more polygons to soften its shape. After one more try, I came up with the following model.

Not bad, I thought to myself, although the snake looks like it swallowed a whole box of Viagra. I guess it will never look quite right if I don’t curl its body in a serpentine fashion, but I won’t be doing that until I animate it.

My next task was to sculpt the inside of its mouth. Whereas a snake’s outer form really is uncomplicated, its mouth is a minor marvel of engineering. Not all snakes have teeth, but the ones that do have two rows of sharp, backward curving teeth at the bottom of their mouth and four rows at the top. These teeth are placed along gummy ridges that are present in all snakes, even the toothless ones. Venomous serpents also have two thick poison glands on the left and right side of the mouth way behind the teeth. Delivery of this toxin is accomplished through the use of two fangs, each of which is connected to a poison gland. Where the fangs are positioned depends on the species of snake. Some fangs are at the front of the mouth and some are way at the back, close to the poison glands. Some fangs don’t move inside the snake’s mouth and therefore have to be short to keep the snake from killing itself. The most impressive fangs come from the likes of vipers, whose long, forward-positioned fangs fold inside the mouth when not in use.

So basically, if I wanted to make life easy for myself, I’d make a toothless hydra with no venom. If I wanted to intimidate the hell out of Chaos Wielder’s players, I’d go for a hydra with six rows of hooked teeth and long fangs that fold inside each mouth. Let’s see, that’s two fangs to animate multiplied by the number of heads that the hydra has…

Decisions, decisions. Which one do I model?

Ugh, modeling that mouth was a real b–… Er, I mean, it was really hard to make. Oftentimes, I couldn’t tell where one polygon began and another ended. Making the UV map was a tough challenge in itself. It’s crude work, but I got the job done.

Okay, so what I have now is a low-poly snake model that looks stiff enough to stab vampires with. I’m not done sculpting, though. My next task is to spruce it up to make it look like a one-headed hydra. Stay tuned.

Sunday, March 4, 2012

Love Is a Many-Headed Thing, Part II

It’s been a while since I’ve worked on the hydra that I wrote about in my last post. Sometimes life takes us in unwanted directions and puts a monkey wrench in our hopes and dreams. Anyhow, I’ve been reading up on creature design, and there’s this adage that goes, “Form follows function.” This means that any creature’s appearance should ultimately be based on what it is capable of doing. I’ve also been reading some fascinating material about adaptations, which are traits or capabilities that evolved in a species to solve a particular problem of survival. Even in fantasy setting, imagined creatures must abide by these principles for readers or players to willingly suspend their disbelief.

Let’s take the hydra. Chaos Wielder, for whom I am creating this model, asked me to work within a couple of parameters in designing the creature:

  • The hydra is a many-headed venomous snake like the monster that appeared in Jason and the Argonauts. In other words, Chaos Wielder wants the classical, mythological hydra, not the many-headed dinosaur from the D&D Monster Manual.
  • The hydra should be appropriate for a swamp setting.

Whether I wanted the hydra to sprout two heads for every one that got chopped off was up to me. Now this is fortunate, because apart from the difficulty of creating a model that could do that, this capability just doesn’t make sense. If the hydra is a vertebrate, as all snakes are, where would the neck bones of the extra head attach to? Isn’t there a physical limit to how many heads a hydra can grow? Otherwise, wouldn’t the whole world eventually be covered with hydra heads and necks?

At this stage, I could see that growing new heads just wasn’t going to happen.

For a snake to have more than one head raises more problems than it solves. Snakes do not bite off chunks of flesh from their meals. They swallow their prey whole. Snakes’ teeth are designed not for tearing off meat but for keeping prey from escaping their mouth. A snake with more than one head would have a tug of war over who gets to swallow their food. This isn’t a what-if scenario. It’s a fact. Like other animals, snakes occasionally give birth to conjoined twins. A two-headed snake could struggle for hours over which head gets to swallow its prey. Having multiple heads is not an adaptation. It is an accident of nature, and the unfortunate creature with this trait is unlikely to pass on its genes to the next generation.

But that’s not all, as they say in infomercials. Looking at stills from Jason and the Argonauts, I had more questions that I probably should have asked before I started modeling the hydra. If the hydra is a serpent, why does it have a bird’s beak? Putting in a trait because it looks frigging awesome isn’t a good enough justification. Remember, form follows function. Also, if the hydra lives in the water, wouldn’t having a split tail make it more difficult for it to swim?

Holy Harryhausen, Batman. After all that work I did on the hydra, I realized I had to start over from scratch. Nevertheless, as they say, no experience is ever wasted. I learned some new creature design principles and 3D modeling techniques.

In case anyone is wondering, I did make progress. Since the hydra is basically a water serpent with many heads, I’ve been creating a 3D model of a snake.

Don’t laugh. It wasn’t easy. More on my next blog post.