This week, graphics professionals and enthusiasts flocked to SIGGRAPH to share and discuss the latest technologies and techniques for making gorgeous computer graphics. The focus of the convention is mainly offline rendering (the stuff that we see in print, movies, and television that's too complex to be rendered in real time), but as computers and game consoles become more powerful, many of these methods and effects make their way into the realm of realtime rendering. Ten years ago, the opening cutscene for Super Mario Galaxy would have needed to be rendered by a cluster of computers and converted into full motion video.
Even though the Wii is not pushing graphical fidelity the way this generation's HD consoles are, we've still come a long way and there's much to be appreciated. There are all sorts of graphical effects that, over the years, have been added to the game artist's palette, and in this edition of Revolutionary, I'd like to draw your attention to a few of them.
When games like Super Mario Galaxy come along, we find ourselves questioning how it's possible for them to look so good, while most other Wii wares have the appearance of games designed for a much weaker platform. It's easy to forget that the Wii's hardware comes from the strong pedigree of Gamecube when much of what we're looking at reeks of Playstation number two.
With multi-platform shovelware, and even a few high profile titles that didn't get any special consideration on the Wii (Guitar Hero 3 and Rock Band, I'm lookin' at you!), developers often drop assets and effects to a lowest common denominator. In the class which Wii is placed, the Playstation 2 has the lowest and most common specs, so our Wii graphics are brought down to its level. The PS2 has had its share of beautiful games, but the methods for making them so beautiful are uncommon enough that they're largely ignored when making games that will have to be replicated on another console in the same class.It's often the first and second party games or that rare, exclusive third-party effort that is given the budget and time to explore the depths of the Wii's fixed-function graphics hardware and pull off something it wasn't expressly designed for. And considering that the core technologies in the Wii were designed nearly a decade ago, there's a lot of "new tricks" that artists and programmers have had to teach the "old dog."
Once hailed as "the new lens flare" (the compliment that ultimately becomes a curse when an an effect's novelty turns into nauseating), bloom was introduced to give games a softer, almost dream-like appearance. It can cover a whole scene like in The Prince of Persia series, or make a glowy halo around lights and shiny surfaces like in Metroid Prime Corruption. We prefer selective, considerate use of bloom to the Vaseline-in-your-eyes smeary overuse in some games.
The Gamecube launched with a game that featured more effects than most Wii games do. The ships in Star Wars: Rogue Squadron: Rogue Leader were more detailed than anything we'd ever seen in any Star Wars game, and much of that detail was "faked" through use of bump mapping. Rogue Leader and its follow-up, Rebel Strike used a primitive form of bump mapping called emboss bump mapping, because it provided good-enough quality without cutting into the high frame rate of the game.
Later Gamecube titles like The Legend of Zelda: Twilight Princess would sparingly use a more advanced effect called environment-mapped bump mapping (EMBM), which conveyed a greater sense of depth and was effective for viewing at more extreme angles. The effect also incorporated specularity, which is the shiny reflective effect on lit surfaces. The wet , bumpy appearance of the walls in Twilight Princess and the uneven surfaces of planetoids in Super Mario Galaxy comes courtesy of EMBM.
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We can't get enough of that bumpy stuff. Normal mapping is another way to make objects with simple models appear more complex. Why go through all that trouble instead of just making a more complex model? Because those models require more polygons, which requires an architecture capable of a higher polygon throughput. When we're talking 100x more polygons needed, the memory and processing requirements can go through the roof, while a bump map or normal map only costs as much memory as another texture layer, enough processing power to calculate the lighting, and a bit more fillrate to draw the effect onto the model. Normal mapping produces more accurate results and at greater angles than EMBM, and is in turn more resource hungry. Also, the Wii and Gamecube hardware need to take unusual measures to produce the effect, which is why it's use has been extremely limited thus far. You can see it in Dewy's Adventure and (reportedly) on most surfaces in the upcoming graphical extravaganza, The Conduit.
One of those graphical elements that's in constant evolution is shadows. They started out as a black circle under a character and gradually became more accurately representative silhouettes, but those blobs still need to conform to the surfaces they fall on and react to variations in lighting. Rogue Leader had self shadowing, which is the effect of having a shadow fall on the object that casts it. That was just one of the many things that blew my mind at the time but still isn't being replicated in many Wii games.
Another launch window title for the Gamecube, Luigi's Mansion had dynamic shadows providing the spooky atmosphere inside the haunted house. Maybe Doom 3 would prove too demanding for a port to the Wii, but it's most noteworthy effect has already been conquered in one of the first Gamecube games.
Fur Shading is a combination of processes that simulates the look and movement of furry materials. It requires a lot of fillrate and a lot of polygon-pushing power to make the effect convincing, but it can greatly enhance the believability of a character or the immersiveness of an environment. I know, there isn't much call for a fur-covered level in a game, but the effect can also be used to create volumetric grass. Star Fox Adventures made liberal use of fur shading for its titular heroic team and the grassy plains on which they traversed. Madden games on the Wii use fur shading to give the Astroturf its 3-dimensional texture.
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Named after the celluloid sheets that cartoons were originally drawn on, cel shading is a term that's generally (but not always) used to classify graphics that have limited color palettes with sharp contrast between light and shadow, and a persistent solid outline when viewed from any angle. Most often it's used for giving a cartoonish appearance to characters, objects, or environments, but its earliest use on the Gamecube was for highlighting realistically-rendered objects on the targeting computer in Rogue Leader. The effect had also been used in a few games the generation, most notably Fear Effect for the Playstation. More recently it's been used to stunning effect in Zack & Wiki and Okami.
Another trick that's been in use since the N64 days in games such as Ridge Racer 64 and Sin & Punishment, motion blur is intended to mimic the out-of-focus appearance of fast motion as caught by a camera. In some games it makes motion appear smoother, while in other applications it is more for dramatic emphasis in a scene, or to suggest an increase in speed. Racing games with "boost" power-ups such as F-Zero GX, Burnout 2, and SSX Blur have employed motion blur when boost is activated.
All these effects (and of course, a lot more) are heavily used on the HD consoles this generation, but with them being possible on the Wii, you'd expect them to be used more often, right? Well, developers have to perform a balancing act, weighing what looks good against what demands too much of the hardware. There's no point in lighting, bump mapping, and casting shadows all over a furry cartoon character if it's going to play like a slideshow.
It's not just Wii games that make limited use of potentially-awesome effects. The Unreal Engine 3 introduced the gaming world to an effect called virtual displacement mapping (also known as parallax mapping), which is essentially the next evolution of bump mapping with the appearance of more depth than normal mapping. A few Rare games used this effect at the Xbox 360's launch, but it hasn't shown up in any UE3 games, and has seemingly been forgotten by developers. PC gamers can enable parallax mapping in the spec-devouring Crysis, but it comes at such a heavy price that most people choose to play without it.
Still, we're hopeful that with hard work, some developers will be able to strike that perfect balance that allows them to go crazy with the effects and turn out a game with the whole enchilada of graphical effects on top of smooth animation and gameplay. Based on historical evidence, I have a few possible candidates.
Factor 5's mystery project
Factor 5's first Wii game, whatever it may be, is practically guaranteed to shatter our preconceptions of how good a Wii game should look. With a 7-year old launch title for the Gamecube, they've already outdone 90% of what's lining the shelves of the Wii section at your local game shop today. They didn't exactly set the world on fire with their PS3 effort, but the bar of expectations isn't set as high on the Wii.
With the Zelda team reportedly hard at work on a new project, we hope that it will make better use of the Wii's hardware than the launch day Gamecube port. Twilight Princess looked great, but we know the system is capable of more, since the Gamecube version was nearly identical. If Zelda Wii is as maturely themed as Twilight Princess, then that could be reflected in a visual style that makes use of dynamic shadows and light. Where Twilight Princess had us transforming into a wolf to search for hidden things, the next Zelda could simply hide things in shadow and make us reveal them with a light. Sure, it's recycling Luigi's Mansion's shtick, but in a Zelda package, who's going to complain?.
Resident Evil 5
Unannounced, but on the top of most of our "Do Want" lists, there's some likelihood that the title is secretly in development to appease we Nintendo fanboys who have kept the series popular for the past few years. The HD versions of the game will make heavy use of light and shadow to evolve the fear-inducing mechanics, so we'd expect no different from a Wii version. A lot of effects would have to be cut down or dropped to squeeze RE5 onto the RE4 engine, but Capcom really seems to know what its doing with the hardware as shown in games like Zack & Wiki and Resident Evil: Umbrella Chronicles.