Virtual reality technology-3D navigation plus novel interfaces-is being used to bring improved entertainment experiences to greater and greater numbers of people. This chapter examines how principles of good game design dating back to the best 2D sprite-based games can enhance the design of newer, 3D entertainment environments. In addition, some problems found exclusively in 3D are described and solved. Everything described here has been implemented and tested in products under development.
The current excitement over creating 3D virtual environments has, for the most part, overemphasized the technology and lacked focus on the quality of the actual experience. The original Super Mario Bros. and Zelda series of games developed over the last ten years and published by Nintendo provide a greater virtual experience than 95 percent of the 3D games being published today. Virtual environment designers must carefully consider what made those early games so appealing and apply the same principles today, albeit in a different presentation style. This chapter examines the following list of key game design principles:
Then, the chapter addresses three problems inherent in 3D environments that must be solved in any good entertainment application:
The classic games (except some driving games) all have an amazing attribute in common-that of third-person point of view (POV). Many driving games, even today, that strive for a straight-through-the-windshield view still allow a third-person POV. By contrast, the vast majority of 3D VR games or experiences adopt a first-person point-of-view wherein your own character is not visible.
There are two good reasons for adopting the first-person POV:
The first-person POV is easier to implement in a 3D world (and nearly impossible in a 2D world) because several issues, as detailed shortly, are instantly sidestepped. Most importantly, management of depth perception is extremely easy: Game players or viewers simply draw straight lines from their view to anything they see: If it's big, it's close; if it's small, it's far away.
The first-person POV is easier to sell (in other words, to get someone excited about funding) because it provides a more visceral experience, and that's what the majority of game and interactive development today is about. Each game tries to top the previous top game's "rush" of graphics, which is easiest to do with first-person POV. However, this places enormous limitations on the depth of the experience that is possible.
First-person POV is a good first step for the industry, but it must evolve to support third-person POV in order to grow and to attract an audience beyond those looking for a rush. Admittedly, a VR skiing attraction might not be as much fun in third person, where one can see the skier one is controlling, because most of the fun of skiing is in the rush. Skiing (downhill skiing at established resorts) is not about exploring, learning, and discovering.
By contrast, the best 2D games are about these very things. While nearly all popular games, it seems, have an action component, the enduring games also create an environment-even in two dimensions-that invites the player to explore, learn, and discover.
Imagine we want to develop a 3D VR Web site for some commercial purpose. Our first thought will be to provide some kind of visceral experience to attract people. A 3D environment where the world whirls about will attract a certain number of people-mostly males, ages 18 to 35. But now that we have people visiting our Web site, it's probably more important that we encourage them to explore, learn, and discover. We want them to explore so that they'll stay active in our site. We want them to learn our product; otherwise, there's probably no commercial reason to create the site. We want them to discover because it's the internal feeling of "Aha!" that gives intense pleasure and rewards our visitors for coming to our site. This critically important Aha! experience can only be created through careful design; it's not something that comes via a purely visceral experience.
In a Mario Bros. game, the first thing you have to do is jump on a Koopa (that's an enemy sprite for the Mario-impaired). But the second thing you have to do is to navigate a series of blocks; this forces you to explore how your character moves and how the environment reacts to your character.
In a first-person POV game, your character's movement is very limited. In fact, your character doesn't move at all; instead, the world swirls around it. But there is a linear relationship between you, your character, and the world (Figure 13.1).
Figure 13.1: Relationship of user to character in first-person POV.
In a third-person POV game, the experience is more complex (Figure 13.2). This triangular relationship between you, your character, and the world provides much greater opportunities for interaction.
Why? Because of your ability to see your character in the world, your mind can see more complex relationships. Instead of a more intense "in-body" experience as with first-person POV, you have a transcendent "out-of-body" experience. That is the real potential of VR-to give you experiences not available in normal life-and third-person POV provides an increased context in which to act and react.
Discovery and Exploration
The act of discovery is what creates the Aha! experience and can be something as simple as realizing that a certain shape in the landscape means you can get help there. Discovery is what cruising the Web is about. Discovering new information is fine, but, in the design of a 3D environment, it's also important that visitors learn to discover "how to" and not just "what." In a Mario game, with a little experience, you learn that you can double-jump and whack two Koopas in one motion. In a 3D VR Web site, for example, where you've created an online store, you would want visitors to learn "how to" by exploring and discovering.
You may need to manipulate your visitors into having this Aha! experience. For instance, you might program your store-clerk character to purposefully get in the way of a new visitor so that your visitor learns to ask the clerk questions.
Figure 13.22: Relationship of user to character in third-person POV.
One final note on third-person presentation: Very few movies are made in the first-person mode, yet moviemakers obviously want you to identify with the main character to develop an empathetic link. If you watch a young child (6 to 12 years old) play Mario Bros., you'll see that the child identifies so completely with Mario that the child "projects" into the 2D environment. You can create this same sense of identification in 3D without resorting to a first-person through-the-helmet view.
Movement Versus Animation
In a substantial VR world where objects may be extremely distant, the movement of an object in the world is more important than any fancy animated details. Up close and personal, animated nuances can provide all sorts of visual clues about the character you are interacting with. But more attention must be paid to how these characters or objects move within the environment than is currently being spent because, in a truly rich 3D VR world, there will be a huge number of objects but only a few that the viewer is attending to actively at any one time.
These objects may exist in the environment to attract the viewer's attention and encourage him or her to explore in a particular direction. Extremely detailed, complex character animation is wasted at such a time, when the object may be only a few pixels on the screen. But an amazing thing about people is that we can tell whether that's a person or a robot off in the distance by the motion of the object in the environment. If it bobs up and down like a person walks, then it's probably a person. If it glides a little too smoothly, it's probably not a person, at least as we know them. The simple motion of a few pixels bobbing up and down is enough to clue the viewer that "Hey, there's another person over there!" Particularly if the motion is oversampled and the motion is displayed in a subpixel, anti-aliased environment, very few pixels can express a great deal.
Ask any player what he or she likes about Mario Bros. games, and the answer is always the same: control. It's certainly not the graphics. My early experience with VR Web browsers is that they leave me feeling horribly out-of-control of my experience. I'm never quite sure where I'm going to end up or why. There are a lot of technical reasons for this, including latency problems and erratic frame rates, but the problem can be solved even under these conditions by switching to a third-person POV. If I can see myself in the scene, and how I move in relationship to other objects in the scene, then I feel much more in control. If something is bumping me from behind, I can see it. I'm not left in a semiparanoid state where I have no idea what's affecting my character and therefore me.
Even if your user interface is dedicated to first-person POV, you can still increase the sense of player control in complex environments by allowing your viewer to move an icon, perhaps shaped like a camera, through the scene, position it in a safe place, and then switch to that view. I know from personal experience setting up architectural walk-through animations that it's easier to create an animation by manipulating a camera icon in the scene than by trying to animate by looking through the camera. The final goal is the same-a first-person experience of walking through a building-but the control necessary to navigate the environment is first provided through the third-person interface.