A Day at Valve

I recently had the chance to visit Valve in order to learn all about the High Dynamic Range rendering technology that will be featured in all of the company's projects from now on. Valve's first release featuring HDR will be the hotly-anticipated Day of Defeat: Source, which ships September 26. The company has already begun preloading the game through Steam. Valve managing director Gabe Newell made a point to ensure that the launch would not be the "disaster" in the vein of Half-Life 2's launch. Only a couple weeks after Day of Defeat: Source launches, gamers will be able to get their hands on the short single-player HDR showcase Lost Coast. Somewhere down the line, probably in November and definitely by the end of the year, Valve will also release Aftermath, the first full-on single-player expansion for Half-Life 2. There's also the Xbox version of Half-Life 2, which Valve mainly sees as a way to get the game into the hands of those who haven't yet gotten a chance to play it on a PC. Beyond that, it's anybody's guess. The team has its hands more than full at the moment, so we'll just have to sit it out for news of what's coming next. Valve and HDR

So what is HDR? It proved so difficult to implement that Valve had to cancel its inclusion in the original Half-Life 2 game, but why? Succinctly, HDR is probably best explained by Paul Debevec, the man who was pioneering HDR research long before it was the type of thing even being considered in video games.

"The 'dynamic range' of a scene is the contrast ratio between its brightest and darkest parts. A plate of evenly-lit mashed potatoes outside on a cloudy day is low dynamic range. The interior of an ornate cathedral with light streaming in through its stained-glass windows is high dynamic range. In fact, any scene in which the light sources can be seen directly is high dynamic range."

HDR rendering attempts to compensate for the relatively limited contrast range of display devices--such as computer monitors--through various means. The first is blooming, which has become a fairly commonly used visual technique in games recently, though it is only one part of what Valve considers a more complete HDR solution. In order to simulate the overexposure of a camera or the eye due to very bright light, the brightly lit portions of the scene are blurred, giving that familiar effect from games such as Far Cry.

Next, there's the use of an HDR skybox. Multiple versions of the sky texture at different exposure levels are painted, so that the game can adjust the exposure in real time depending on a variety of factors. This is an impressive feature that allows for the entire scene to be dynamically relit based only on changing the exposure levels. A very impressive part of Lost Coast is that there is literally only one source of light in the entire level: the sun (well, and your flashlight and gunfire). Thus, when its exposure is adjusted, it affects the lighting everywhere. One thing that causes exposure adjustment, just as in real life, is moving from a very dark area to a very bright area, or vice versa. When your eye experiences a drastic change in perceived brightness, there is a moment during which the iris adjusts. The game too has that auto-exposure affect. In fact, Valve is hoping that the mod community will find interesting ways to manipulate exposure as a gameplay element. Perhaps it would be a key feature in stealth games where light and dark make all the difference. There were even suggestions such as binding exposure adjustment to the mousewheel. For what purpose? Valve has no idea, but they hope somebody else will.

One of the most visually impressive parts of HDR is that it allows higher light values than would normally be allowed in a game engine for surfaces that aren't very reflective. For example, consider sand on a beach that is in general 20% reflective. Without HDR, that sand would only be able to use 20% of your monitor's maximum brightness, leading to a fairly low contrast range. However, in reality, the sun is such an incredibly powerful source of light that on a bright clear day, it will still cause quite a lot of light to reflect off of the beach, and can have a blown out white effect; this is represented in the game. The same goes for water; if the sky is very bright, the water will reflect it as such. All in all, it's a very impressive technology to which Valve has really dedicated a lot of time and effort. One testament to the artistry with which the company is implementing HDR is that, with the exception of fairly obvious effects such as blooming, many of the improvements to normal lighting are almost transparent. There were several moments when I didn't realize how much of a difference the techniques made until they were put side to side with traditional low dynamic range screenshots, simply because the HDR scenes looked more "right". As gamers we are often used to measuring graphical improvements in terms of higher polygon counts and visual pyrotechnics, and while some elements of HDR definitely provide a lot of showy effects, much of it is very subtle and fundamental. Continue to the next page for my impressions of Lost Coast and Day of Defeat: Source, as well as more on Valve. _PAGE_BREAK_ The Lost Coast

So all of this description really doesn't mean much without a game to show it off, and that's what Lost Coast is for. It's worth saying right up front, however, that there isn't all that much game there. The amount of time you'll reasonable squeeze out of the single level is better measured in minutes than hours, and even then you won't have to measure much. The level can be completed in about fifteen minutes from start to end, although it looks gorgeous enough that you might want to spend some time admiring the water and moving in and out of dark places to induce auto-exposure. Plus, there's always the commentary track. Yep, there's a commentary track. It's a great way to add extra value to an otherwise straightforward gameplay experience. When you have commentary mode enabled, there are rotating speech bubbles scattered at key places throughout the level. Moving onto one and pressing the use key will begin a recorded message by any one of several members of the Lost Coast development team explaining a particular technique or design feature that went into the level's creation. The first one, introducing the player to the level, begins "Hi, this is Gabe Newell, and welcome to the Lost Coast. In this tour, we're going to be talking about a new graphics technology we've been developing called High Dynamic Range, or HDR. We'll also be giving you some insight into the design and production challenges we faced during the construction of the Lost Coast..."

It's a pretty unique thing to include in a professionally-designed game, but it makes perfect sense given the popularity of DVD commentary tracks. In fact, Valve enjoyed working on the feature and plans to include it in future game releases as well if player response is positive. In Lost Coast, much of the commentary is devoted to the HDR technology, being the primary reason for the level's existence, but there's also discussion of general Valve design philosophies and artistic techniques. For example, the fisherman NPC in Lost Coast is a new direction for Valve's modelling techniques. Unlike just about all the characters in Half-Life 2, he is not based on a specific human model or composite of models. Rather, he was designed from scratch, resulting in a very organic and specific look. He is also much more detailed than most of Valve's models, with a greater level of detail as well as being specifically designed to take advantage of HDR. In fact, Valve says there's a big different between designing LDR and HDR content; you can't simply bolt the technology on to existing levels and models, because there are many lighting issues that must be taken into account. As far as the actual game content of Lost Coast, you find yourself on the shores of a beach where you encounter a lone fisherman. He explains that the Combine have set up a large gun in

a nearby church, and of course it's up to you, as the legendary and heroic Gordon Freeman, to take care of business. You travel up some cliffs overlooking Ravenholm--which ties into the very small story presented in Lost Coast--before arriving at a gorgeous Byzantine church (the commentary points out that, unlike basically every other video game that has ever contained a church, this is in fact not in the Gothic style). The church is a wonderful display of the technology Valve has been working on for the last few years, and there are all sorts of reflective surfaces, stained glass windows, dark and light areas, and all sorts of other design elements that take advantage of well-lit goodness. Despite the technology-focused slant of Valve's presenation, I did make a point to ask Gabe Newell if he had anything to say about the gameplay and atmosphere of Lost Coast distinct from the visuals. After thinking for a moment, he responded cryptically, "There's a reason the cathedral is important. You can't really know why yet." Sadly, he gave the impression that further questioning would get me nowhere. At least part of the explanation of that statement is revealed in the game, but it sounds like there might be more. I'm a bit reluctant to say too much more about Lost Coast, simply because it's short enough (and free enough) that you might as well just not have what's there spoiled. As long as you aren't expecting anything more than a single beautiful level, you won't be disappointed. Day of Defeat: Source

Fans of Day of Defeat have been awaiting the Source update for a while now, and now that the game has begun preloading over Steam, the wait is just about at its end. DoD is an online World War II team-based action game. It's a more realistic experience than many online PC shooters, though unlike in games such as Counter-Strike, players still respawn in the same round after dying. Players represent either American and British troops or German troops, and choose from a variety of classes, which determines the type of weapons they will be using in that round: machine guns, close range-oriented weapons, sniper rifles, and so on. Gameplay objectives range from various scenarios based around offensive and defensive goals, to maps requiring both teams to try and capture more flag-marked territories. The map being demonstrated during the presentation was one based around territory control. So that's all old news. The biggest addition to Day of Defeat: Source is, quite simply, Source. The game looks worlds better than its predecessor, and it sports the latest iteration of Valve's engine. The textures are very detailed and the level being played, which was modeled quite successfully after a small Italian town, was a pleasure to observe. Valve noted that one of the artists who does textures for roads and tiling and so on models them first as actual geometry, then renders then in 2D and normal maps them for realistic effect.

The graphical improvements of course include the new HDR rendering, which was deliberately toned down a bit from its implementation in Lost Coast. The most striking way to see the improvements made to Day of Defeat is to see it running with and without HDR (which can be toggled in the video options), because it does not feature as many huge blown-out bloom effects and other obvious such displays that are present in Lost Coast. One theme running throughout the presentation is that since HDR is a technology that adjusts lighting in real-time depending on where the player is moving and looking, it greatly impacts game design. Thus, in a precision-oriented multiplayer game such as Day of Defeat, it makes more sense not to overwhelm players with blindness and outrageous bloom when they're trying to make a solid headshot. That said, all of the Source improvements to the game are very attractive and often subtly tasteful, and though it doesn't seem that the actual gameplay is evolving greatly, Day of Defeat: Source should provide a nice visual update for a game that's getting up there in years. The game will be available to play September 26 with four maps. When asked about plans for additional maps, Valve simply responded, "More of them." They indicated that they would be releasing new content on a periodic basis, and also expect to see great things from the mod community. Continue to the next page for some final tidbits from Valve. _PAGE_BREAK_ Valve on the Mod Community When Lost Coast is made available for download, Valve plans to update Half-Life 2's SDK to include HDR documentation. It will explain how to create maps that contain both LDR and HDR lighting, to accomodate players that do not have video cards capable of HDR. The SDK will also contain the skybox Valve used in Lost Coast, because it is apparently a considerable feat to create images supporting HDR data using the current tools such as Photoshop. Adobe has apparently been a bit slow in updating their software in this regard, so Valve ended up hand-authoring the skybox completely, a task with which they don't expect everybody will want to bother. The SDK will also explain how to adjust exposure levels, the brightness range that the auto-exposure feature will cover, the amount of bloom to use, and so on. There are key things to take into account; for example, just as in real life, when looking from a very dark area into a very light area, it is actually more difficult to make out details due to objects being so heavily shadowed. Though Valve has yet to fully explore the gameplay ramifications of HDR, they are clearly visibly excited to get the tools into the hands of the resourceful mod community to see what kind of ideas will come to fruition. Essentially, they hope to see the Counter-Strike or Garry's Mod of HDR, and they're confident somebody will come up with it. Valve's Content Strategy Episodic content seems to be picking up steam (ha! ha!) in the industry lately, with the first episode of Telltale's Bone adventure series just released, Ritual's SiN Episodes on the way, and Valve getting ready to ship Aftermath. Gabe Newell was very firm about Valve's devotion to delivering more content to players by way of a tighter development cycle than Half-Life 2's epic five-year journey. He explained how demotivating it can be to ship an enormously ambitious project, only to start right up again on another. It was much easier to get team members excited about smaller projects such as Lost Coast, Day of Defeat: Source, and Aftermath that it would have been to say, "Well, let's get started on Half-Life 3." The teams are smaller, the development cycles are shorter, it's easier to implement feedback, there's lower risk to the developer--essentially, Valve thinks it's the way to go. As Newell put it, "Breaking a five-year project into five one-year projects gives better efficiency, better value, better quality control." As projects get longer and longer, the inefficiency and potential obscure bugs that can occur grows exponentially. One benefit of this method is that Valve can continue developing noteworthy pieces of technology which they will be able to get into the hands of customers as they are perfected rather than years after they are done or before they are really ready. Lost Coast is one example of that. HDR was going to be implemented into Half-Life 2, but proved to be not worth delaying the game even more. The current version of HDR is in fact the fourth discrete iteration of the technology Valve has developed due to prior methods not giving a desirable enough compromise of performance and payoff. As always, Newell invites feedback via email. Aftermath Aftermath will be the first big test of that philosophy. The game will ship over Steam this year, most likely in November, and will have an incredibly reasonable purchase price of $12.95. Valve hopes to analyze customer feedback (of which there is always plenty, they note) and incorporate that feedback into their design decisions in the next piece of episodic content, which will clearly come out much sooner than Another Half-Life Game would. Newell also revealed that, for those who were curious, the voice at the end of the end of the Aftermath trailer is in fact that of the G-Man. No further details were divulged. Newell on Physics Cards Gabe Newell offered his own opinions on standalone physics processors. He is by no means against them, but he doesn't think they will succeed without a definitive killer app. Though Valve is currently not developing any such game, he invites the mod community to create something that will demand the kind of physics processing power that a standalone card would provide. Were this to occur, Valve would be happy to cooperative in the endeavor and add support to their products. So get to it, modders. Half-Life 2 Still Stuttering? If you're still experiencing unintended audio stuttering problems in Half-Life 2, Erik at Valve invites users to email him personally, and he will do his best to get you all fixed up. He notes that the problem has been found to occur due to a very wide variety of causes, so it's more effective to help on a one-on-one basis than through generic troubleshooting. Gabe Newell Behind a Valve, Near a Golden Crowbar