2D + 2D = 3D pt.5

Part 1. Part 2. Part 3. Part 4.

Navigating, interacting, and interpreting 3D space is too difficult for the average gamer. When Mario 64 came out, we all had to learn that perspective is a key factor with 3D games. To play this 3D platformer well, players had to master Mario's moves as well as the camera control. Not only does the camera provide the game view, but the camera position also affects the player's controls. To experience this effect first hand, try moving Mario in a straight line toward any target while constantly spinning the camera around. If you do this, you'll quickly understand that to keep Mario moving straight, you have to compensate by rotating the analog stick in the opposite direction of the camera rotation and at the same rate.

Mario's movement controls have always been relative to how we view the game world. In Super Mario Brothers, a 2D side-scrolling platformer, holding right always moved Mario to the right and toward the end of the level. In a 3D game, how we view the gameworld changes relativity of the controls. Understanding the relationship between the camera perspective and the controls requires constantly triangulating the positions between the Mario (the player avatar), the target, and the camera position. Such calculations are more than most people are willing to actively do. Fortunately, most gamers have naturally developed a few tricks that simplify the 3D space and 3D triangulations.

I've watched many people play Super Mario 64. When up against tricky platforming challenges, the gamers that weren't comfortable triangulating the game space used an interesting technique. By moving the camera so that the perspective lines up directly behind Mario, players essentially change the 3D perspective challenge, into a 2D challenge. Now the player only has to focus on moving forward and JUMPing at the right time. In other words, the 3 points/factors that make up the triangulation can be manipulated into 2D line, which is a much simpler geometric shape.

Simplifying 3D doesn't just happen in 3D platformers. All 3D games with a player controlled camera system have the potential to simplify or clutter the fidelity of the game perspective. To help us out, developers have designed mechanics that help to simplify 3D gameplay.

Simplifying 3D

Super Mario 64 showed the world how 3D spaces, mechanics, and cameras can be designed to take advantage of they dynamics of 3D space. Unlike the 2D Mario platformers that came before it, the enemy design and influence in Mario 64 is very minimal. With such a volume of space to platform in, enemies are much more infrequent, must less effective, and no longer a critical element in what makes the game's challenges challenging. Now that players have 8 health points, Mario can take several hits before dying. And if a player is ever low on health, a few coins or some water can restore Mario's health. Mario 64 isn't designed around combat.

It wasn't until The Legend of Zelda: Ocarina of Time (OOT) that 3D combat was revolutionzied. Just like with their 2D games, the difference between Mario and Zelda's enemies are great. In OOT, enemies are designed with greater degree of complexity. They will seek you out using pathfinding, strafe around you, go on the attack, switch to defense, run away from you, wait for you to get close, shoot you at range, etc. Zelda enemies can exist at any point in 3D space around Link. Enemies in Zelda can swim in the water at your feet, fight you on the ground, hover just above the ground, or fly around high into the air. When fighting these enemies OOT gives players a range of perspective changing design techniques/mechanics that increasingly simplify the 3D gameplay into 2D gameplay. The first design feature I want to cover is functionally equivalent to when players line up the camera in Super Mario 64 to make difficult jumps.

Lock-on Mechanics & Relative Space

I know the discussion is on OOT, but this image is just too awesome.

By holding the Z button on the N64 controller, players are able to lock the camera view behind Link and a pointed squarely on a target. If Link moves when locked on, the camera stays behind him. If the target moves, the camera swivels to stay focused on it. When locked-on, forward and back movement is relative to the target. At the same time, side to side movement is also relative causing Link to circle strafe around the target.

Along with the focused perspective and altered movement capabilities, the lock-on mechanic also uses pathfinding or auto-aim to point all of the player's attacks at the target. Whether the player uses sword strikes or projectiles, they are always automatically aimed at the target. This is significant because of how a 2D plane of relative space is created between the player and the target. With either grounded or flying enemies, when the aim is auto adjusted in this way, the necessity to triangulate between the avatar, target, and camera is eliminated. Locking on creates a functional line of intent between the player and the target. With only 2 points/factors to consider (avatar vs. target) the 3D space the factors take up is simplified to a 2D relationship.

Other games that use lock-on mechanics are DMC4, Ninja Gaiden Sigma, and all of the 3D Zelda games. Games like Katamari Damacy and Super Monkey Ball feature a camera system that is locked behind the player avatar's back. This design helps simplify the perspective of the game and the camera control. Taking the concept of combined player and camera controls, there is a type of 3D perspective that offers freedom of movement, freedom of aim, and a fixed perspective. For these reasons this perspective greatly simplifies 3D gameplay, which is probably the reason why it is so popular today.

The First Person Perspective

You can watch the boss fight here.

The first person perspective shows a game world through the eyes of the player avatar. In games that give the player camera/view control,  the player is put in control of viewing the game world. Compared to the 2D perspectives and 3rd person perspectives, the FP perspective is the most limiting game view (see image above). Players are limited to a narrow cone of vision that displays much less than what is contained inside the average human vision range. For these reasons, the player must actively look around to understand the world around him/her. In this way, understanding the 3D world is a core dynamic.

With first person shooters, looking and aiming are one. When holding a gun, everything you see is set along the sights of the firearm. With dual analog, keyboard and mouse, or Wiimote + Nunchuck controls, aiming/looking is essentially 2D. Because guns are such accurate and powerful weapons, when firing bullet like projectiles the 3D space between the gun barrel and the target is compressed and almost entirely minimized. In other words, when you pull the trigger, if the target is in your sights it's a hit. If the target is not, it's a miss. In this way, FPS aiming and shooting is functionally 2D.

Many people think that FPSs are fairly simple. The left stick controls the character movement like a top down game. The right stick controls the aim and perspective in 2D. To hit targets, one needs to only align the reticle and push a button. Combining these two systems allows for players to move through 3D space, but at the same time simplify 3D space by compressing it into functionally 2D space.

From Super Mario Galaxy to Halo 3, understanding 3D gameplay games consist of understanding the mechanics, perspective, and how the 2D inputs from the game controllers translate into the 3D space. Now, with the Wiimote, the Sixaxis, and even the Novint Falcon games can finally let players control 3D mechanics using 3D inputs.

3D Mechanics/Input/Interaction

The Wiimote is to 3D control, as the touch screen is writing/drawing controls. Sure, with a lot of practice you can become quite a competent artist using a D-pad. But writing or drawing in this way isn't isn't as intuitive or as versatile as using a touch screen. In the same way, nothing can be more intuitive for a 3D mechanic/interaction than a 3D input.

Take Wii Sports Tennis for example. With one motion of the Wiimote, I can put a variable amount of spin on the ball, hit it toward a specific side of the court, launch it a specific distance upward, and drive it with a specific amount of force forward. In other words, I can control the power, direction, and spin of the ball all in one intuitive motion. If Wii Sports Tennis were designed around a more traditional controller, there would probably be separate buttons for the lob, slice, and top spin shots in addition to the ability to hold down each button for increased power. The Wiimote Wii Sports Tennis design simplifies the controls by removing buttons and making the motions intuitive while keeping the directness of the mechanics very high. All of the Wii Sports games are designed with this level of 3D intuitive and direct mechanics.

 

Excite Truck: In this game players can land their trucks from the air on all four tires for a speed boost. Because the terrain is so uneven, bumpy, and hilly, landing on all tires requires the player to angle the truck beforehand in mid air. Controlling the truck is as simple as tilting the Wiimote as if it were the handle bars of your truck. Turning and tiling the truck in mid air engages all 3 dimensions, making the air control mechanic a 3D controlled mechanic in a full 3D gameplay game.

These 3D motion controls also create a new kind of perspective that's based on how you play the game as opposed to how the camera displays the game world. The direction Mario moves when pushing the analog stick in one direction is dependant on the camera position. But no matter how the camera is positioned in Wii Sports Tennis, swinging the Wiimote the same way will always produce the same effect because of how the motion controls are intuitively designed to mimic real life tennis swings.

We have come to the end of a long and detailed look at 2D and 3D dynamics and game design. Hopefully, now you understand that 3D space is little more than an added dimension that changes everything in the world of game design. So many have made 3D games, and so many have missed the mark in one way or another. It's not surprising that the Mario and Zelda games provided such excellent examples for side-scrolling, top down, and 3D game design. After experiencing Super Mario Galaxy and The Legend of Zelda: Twilight Princess, two games in two long running series of 3D space and game design innovators, I know that video games are capable of even greater levels of design.

Perhaps the next step for 3D gaming is head tracking.

2D + 2D = 3D pt.4

Continuing from part 3...

3D Punctuation

Many 3D games don't use all 3 dimensions evenly. For these games, the gameplay is mostly either 2D side-scrolling or 2D top down while only occasionally using the Z or Y axis respectively. I describe such games as punctuating the 3rd dimension. The range for this classification includes games that shift between quantified dimensions to games that fall just short of supporting gameplay dynamics that use every dimension evenly. The best way to go about understanding the distinction between 3D punctuating games and full 3D games is to look at examples that gradually move from one end of the spectrum to the other.

Quantified Dimensions

• flOw: In this game, players swim around in a 2D top down horizontal "slice" of the ocean. By eating special ocean elements, players can move vertically between these slices of the sea. In this way, the player is able to explore every dimension of this game world, yet vertical travel is restricted to separate levels. Play it here.

• LittleBigPlanet: LBP is just the opposite of flOw. Instead of playing in a top down world while punctuating the Y dimension in quantified zones, LBP exists in a side-scrolling world where players punctuate the Z (depth) dimension by switching back and forth between the 3 layers/zones. The biggest difference between these two games is that in LBP ,the Z axis zones are much more integrated into the gameplay. Not only can players switch back and forth between the zones using their MOVE mechanic, but level elements are often designed so that they extend into more than one zone at a time. Also, players can grab point bubbles from any zone, and explosion blast radius affects all three zones. In these ways, the 3D depth of LBP is less separate than in flOw.

Analog 3D with Minimal to Sub Full 3D Gameplay

• Teenage Mutant Ninja Turtles 2 (NES): Players can move in 2 dimensions along the ground; up, down, left, right. To dodge attacks or obstacles, players can jump vertically along the Y axis. Because JUMPing is not a major part of the game (ie. not required for progression) and gravity isn't a key dynamic for the level/enemy design, this 3rd dimension of vertical space only serves to punctuate what would otherwise be 2D top down gameplay. Play it here.

• Mario Strikers Charged (Wii): In this soccer-hockey hybrid, players run around the field in top down gameplay fashion. Certain characters doing certain moves have the ability to jump up into the air (along the Y axis). When this happens, the game uses the 3D hitboxes to determine if these jumps avoid oncoming tackles or incoming projectiles in real time. In addition to kicking the ball along the ground, the ball can be kicked into the air via lob passes, shots on the goal, and lobs into the goal. Because everything on the field can interact with each other according to an accurately drawn hitbox, small differences in height can make a big difference in the gameplay. For these reasons, Mario Strikers Charged uses the 3rd dimension to enhance and punctuate gameplay in a more organic and dyanmic way than in TMNT2 (above). Watch a high level 1v1 match here.

• Pikmin 1 & 2 (GCN): Though the presentation in the Pikmin series is top down (or very nearly so) the gameplay is surprisingly 3 dimensional. While traversing the land, players have to maneuver up, over, around, and under objects, ramps, hills, enemy bodies, etc. The multilayered and bumpy terrain punctuate the 3D game space. While walking up a small hill or climbing down a small slanted surface would ordinarily be a very minimal use of 3D space, in Pikmin the verticality of the Y axis and gravity are a key dynamic to the level and enemy design. The player avatar in Pikmin is limited on where he/she can go by the level obstacles/design. Because these obstacles exist in 3D space with 3D hitboxes, it's possible to throw something up and over them. In this case, players have an army of Pikmin at their disposal to throw around and use in a variety of ways. Whether it's throwing Pikmin on the backs of large enemies or up and over ledges to grab treasure Pikmin uses 3D space quite dynamically. Putting all the parts together, Pikmin is a 3D terrain top down RTS that has the flexibility to pull the perspective in close and to the side in order to throw Pikmin, the functional equivalent of a JUMP mechanic.

Full 3D Gameplay

Instead of combining a variety of largely independent design layers to create 3D gameplay like with the examples above, the core dynamics of the following games depend on 3D interactions of 3D objects and 3D space.

• Super Mario 64 (video)/Sunshine (video)/Galaxy (video 1, video 2): All three of these games are about exploring 3D spaces by using Mario's gravity defying JUMP. SM64 established the basic 3D platforming mechanics and 3D level design. Sunshine extended the core mechanics by giving Mario a water "jet pack" that allows him to hover, race forward, and rocket upward to navigate the 3D areas in new ways. Finally, Galaxy innovates on the gravity dynamic itself. By putting Mario out in space running around on little planetoids, gravity becomes local, variable, interactive, and almost tangible. In this game, absolute direction is irrelevant. After all, when running away from a target can quickly change into running towards it, or when jumping up can so easily change into falling down, motion is only relative to where you're going next.

• Echochrome (PSN) (video): Taking the limitations of 3D space and perspective and incorporating this engaging quality of the 3rd dimension into the core dynamic of this puzzle game, Echochrome is a perfect example of 3D dependant gameplay and 3D interpretation. The gameplay revolves around manipulating the perspective of these 3D structures to reveal and obscure parts of the level. When obscured, the game functions like these parts don't exist. When positioned just right, 3D space is bent to function like it appears from a 2D perspective.

• Super Monkey Ball 1 (video) & 2 (video) (GCN): Guiding the monkeys through the levels in this game requires players to tilt the gameworld. Instead of moving the avatar's around, players manipulate the world in a 3D way; tilting. Because of this design, every level in the game (even the flat ones) are moving around in full 3D space. These controls/mechanics are not to mention the intricate ball physics which allow players to JUMP, BOUNCE, and CATCH the monkey balls all by manipulating the tilt of the levels. Compared to the first game, Super Monkey Ball 2's levels are designed with a lot more verticality (y axis) in 3D space. 

For all games that aren't full 3D gameplay games, understanding the 3D design is only a matter of understanding how the underlying 2D systems are put together and/or how the 3rd dimension is punctuated. But there's another important issue that has plague 3D game design that must be discussed. If perspective is a new dynamic for 3D game spaces, then a game's camera design can make or break the gameplay. In part 5, I'll uncover why camera design is so inherently tricky, and what designers have done to simplify 3D back into 2D.

2D + 2D = 3D pt.3

In part 1 of this series I covered some common conventions and design features of 2D side-scrolling and 2D top down games. As the title of this series suggests, understanding 3D game design is a matter of understanding 2D game design. In part 2, I gave many examples of 2D side scrolling/top down games in addition to a few special cases. Now it's time to look at 3D games.

There is obviously a difference between 3D graphics and 3D gameplay.

Wii Fit Jogging is an example of a 1D game with 3D graphics while Track and Field is an example of a 1D game with 2D graphics.

Street Fighter HD Remix is an example of a 2D side-scrolling game with 2D graphics while Super Smash Brothers Brawl is an example of a 2D side-scrolling game with 3D graphics.

The legend of Zelda 4 Swords is a 2D top down game with 2D graphics while StarCraft 2 is a top down game with 3D graphics.

Super Mario Galaxy is a 3D game with 3D graphics, and Mario Kart Super Circuit is a 3D game with 2D graphics.

Because 1D, 2D, and 3D games can be made with 2D or 3D graphics, the graphical presentation of a game does not tell anything about the kind of gameplay a game supports. Regardless of how a game looks, understanding how a game creates 3D gameplay and whether or not the 3rd dimension is significantly used requires a close look at the specific mechanics and design of a game. First we must consider...

The Dynamics of 3D Space and Perspective

Objects in a 3D game are representational as opposed to presentational like in side-scrolling/top down games. 2D graphical games typically take 2D sprite images and code the images to create a game object. This object typically retains its proportions and visual form throughout the game. For example, all the Goomba in Super Mario Brothers act the same and look nearly identical.

But in a 3D game perspective creates new dynamic. How you view a 3D object changes the way it appears. Now you can view a simple box from the top (like in a top down game), the side (like in a side-scroller), from any angle, and from almost any distance. Instead of the artists creating a 2D image of a box that must clearly communicate to the player that it's a box, the 3D graphic designers create a model of a box so that the player can view it in as many different ways as possible.

The same small box from many different angles.

Instead of using relatively simple visuals like with a 2D side-scroller or top down game where the Z and Y axes respectively exist in a significant level of interpretation, 3D games uses a far more organic kind of interpretation. Essentially, when viewing anything in 3D space, you're looking at a 3 dimensional object through a 2D lens or viewpoint. Your perspective gives you a unique viewpoint that reveals and obscures parts of that object. What you can't see, you interpret. As you move your viewpoint, your interpretation is updated. But, in any 3D environment there's always something you can't see from your current view. In other words, you always have a blind spot whether it's behind your "head" or on the other side of an object. This is the inherent limitation of 3D space and perspective and what makes 3D environments and objects so engaging to explore. No matter what you do and how much you can see, there's always a feeling that there's more too see. Whether it's looking behind a crate, crawling into hidden spaces, or spinning the 3D models around there's always a sense of verifying, understanding, and discovery.

With 3D video games (especially ones with 3D graphics), the natural dynamics of space and perspective must be embraced. Like the dynamics of gravity, the dynamics of space and perspective are inherent to 3D graphics. But unlike gravity, the shifting interpretation of 3D objects and the limitations of 3D perspective are constantly changing. On a moment to moment basis, the gravitational constant in side-scrolling games never changes. In a 3D game world, every time the perspective moves, the game world changes. Failing to design around the inherent dynamics of 3D space can easily yield games with bad cameras and bad 3D.

Bad 3D/ ba3D/ BA3D: I talked briefly about bad 3D here. Now that we've covered 2D and 3D space more thoroughly I wanted to present a clear definition. Bad 3D: when the perspective of a video game is at such an angle as to significantly obscure an axis of 3D into the zone of interpretation that's needed to make informed decisions.

3D Hit Boxes

With 3D graphics comes an added dimension of form. Because of the dynamics of 3D space and perspective, the form of an object can appear to be one way, yet interact in ways hidden from one's current view. Check out the video at the bottom of this post for an excellent example of how tricky a 2D view of a 3D object can be. For these reasons, the next dynamic of 3D graphics in 3D games is 3D hitboxes, or how 3D objects interact with other 3D objects.

The Link on the left actually has this blobby, yellow body for a hitbox.

A hitbox is the 2D image or 3D model that is calculated by a computer system to determine if an object will collide, hit, stop, or interact with another game object. One wide spread example of 3D hit boxes at work in video game systems is realistic physics. All games with 3D graphics and 3D gameplay has some kind of physics system in place. As long as there's gravity and/or objects can't pass through each other, there are physics at work.

 

When Link swings his sword out to hit an enemy, the exact position of the sword is being calculated at every step of the animation to see if the sword hits any part of the enemy's body. Some game developers fail to draw hitboxes tightly around their visual sprites/models. Failing to do so can create frustrating moments where it looks like you did one thing and the game tells you you did another. In other words, it may look like you dodged an attack, yet the game insists that you've been hit. It may look like you landed on the platform, but the game makes you fall to your doom. Though many games from Super Mario Brothers to Halo tweak their hitboxes for playability, ensuring that the forms (visuals) closely match the function (hitbox interactions) is key. The more accurately a 3D video game draws its hitboxes the tighter the game will be.

Some examples of video games with great 3D hitboxes and object interaction are...

• Katamari Damacy
• Wii Sports: Boxing
• Boom Blox
• Shadow of the Colossus
• Forza Motorsports

 In part 4, I'll cover 3D inputs and the specific styles of 3D gameplay.