By Paul C. Schuytema, Scott McCabe, Steve Hornback, Matt Wood, and John Anderson
Paul Schuytema, project leader:
When you boil things down to the bone, computer games offer extremely limited sensory output. You can’t touch the characters in a game. You can’t smell the environment. Your view is restricted by the field of view that the programmers feel is best. You can hear, but that too is restricted–positional information and audio cues are crude at best when compared with the real world. In short, staring into a computer screen really doesn’t give you a chance to soak up much input. So, like a person who has suffered the loss of a sense, the available senses must overcompensate.
In a computer game, the lion’s share of the sensory burden is upon our eyes. Games are truly a visual medium, and nowhere is technology advancing faster than in the visual realm. Because we invest so much attention in our visual input stream from the computer, the more real the visual, the more likely we are to believe that what we are seeing is real. To suspend disbelief, then, a game must first and foremost convince a player’s eyes.
Yet all of the technology in the world won’t make what we see any more convincing by itself. Technology is the vehicle to deliver the visual content to our eyes–but it is the content that serves as the primary visual trigger. Sure, geometry defines a space and light maps can simulate shadows and brightness, but without additional visual context, the meaning is lost.
Several years ago (only a blip in the geological clock, but a lifetime ago in this industry), a little game appeared called Wolfenstein 3D. Developed by the fledgling id Software and published by Apogee, this game ushered in the age of the texture map. The geometry that constituted Wolf 3D’s world was not flatly shaded–the walls seemed more real than ever before. Bricks looked like bricks and doors like doors. Gone were the flat colors of the past; upon the geometric polygons lay real art–textures.
Texture maps are bitmap image files that can be projected upon the geometric faces of a virtual world. A picture of bricks can make an ordinary flat wall look like a brick wall. An overlaid picture of torn human skin can make a wall look like…well, like something out of Doom or Doom 2. What a great technology revolution it was when this approach of dynamically projecting art upon skewed polygons became the norm. Sure, there are tons of technical issues: How does a projection of a texture appear when the polygon converges on the horizon? Can the image remain stable during a rapid change of views? But those are questions for another time.
Because we know that we can texture freely, does that make our worlds more visually believable? Certainly not. If I were to whip up some brick textures and a few wood textures, would I blow you away? Hardly. Because I have the pixel skill of a manta ray, anything I textured would look as garish as the Saturday morning cartoons of the late 1960s.
No, to facilitate the true suspension of disbelief, we need to make sure true artists create the textures that populate the worlds of Prey. And here they are, in no particular order, discussing their strategies with regard to our game design. Listen up!
It’s All About Textures
Matt Wood, environmentalist:
For the most part, if I want something specific or detailed from an artist, I’ll try to find a picture or example that relates to what I’m thinking. If I can’t find one, however, I might end up drawing it on paper or just doing my best to explain it and have them try to fill in the gaps. I can say, though, that I am never disappointed with the final product. Ninety-nine percent of the time, the texture turns out MUCH better than I had originally envisioned.
John Anderson, environmentalist:
Scott and Steve, our texture artists, do incredible work, so often I can select from their available textures. At times I won’t see a texture that quite fits, so I will show them the designed area. They will either know just what the room needs or they will create something perfect in no time. They continually amaze me with the quality of their work. One caveat is that the texture sizes and variety used must also be kept in check. Too many big textures or too many different textures and the room’s frame rate will suffer.
Steve Hornback, texture artist:
Creating realistic textures for game development is my major goal. After all, reality is the name of the game. I can achieve this by:
1) drawing a texture from scratch.
2) scanning a photograph and modifying it.
3) taking my own digital pictures and modifying them if necessary.
4) using canned textures and modifying them.
5) a combination of any of the above.
Many textures must be drawn from scratch because they simply don’t exist in nature. Imagination and talent are very important here, as well as the ability to make a texture look real and not drawn. Additionally, most textures must be “tiled” so they can repeat in any direction. Creating a texture that tiles in all directions without appearing tiled is an art in itself. I still find textures that at first glance look impressive, but when tiled look awful! Trial and error and a lot of experience help here. Nowadays I have a pretty good idea of what will work and what won’t, but even so, I get fooled once in a while.
Scott McCabe, texture artist:
Sometimes (but not often) a texture will be needed, and the only way to make it look real and not drawn is if it’s modeled. So I’ll model and render it out using Lightwave, make some adjustments and bang!–there you go. I try to leave this as the last alternative–as enjoyable as this is, I don’t like making this a habit because it can suck up time like a Hoover vacuum.
Prey and the Technicolor Coat
One of the best advancements over the last few years has been the expansion of the color palette. Games such as Doom and Duke Nukem 3D created seemingly lavish environments with their 256-color palette. While 256 colors allowed artists to pick from the vast majority of major hues, one key factor was missing: subtlety. The new 16- and 24-bit palettes allow artists to add much more depth and realism to their texture tiles.
I’ve been developing games since 1991, when we were using only 16 EGA colors. Since then, games have progressed to a 256-color palette. Now I’m working with millions of colors in a 24-bit palette. With 24-bit, the richness of the palette rewards me with freedom and variety, but at the same time, I face challenges in learning new programs and techniques to take advantage of this richness. As working with a range of 256 colors to create a texture was quite limiting, careful attention had to be paid to the creation of the palette. This concern disappears in a 24-bit palette, where now I’m limited only by the resolution of the image and my imagination. It took me several months to bring myself up to speed on all my 24-bit options. Each day I learn several new techniques for creating my artwork. All things considered, 24-bit rocks!
Because we’re not dealing with 256 colors anymore, there’s so much we can do now. My approach has probably changed more than anyone’s. Now I approach a texture task more like a movie prop. Because of 24-bit color, we can really pull this off much better than the restrictive 256-color modes. We should be able to pull off more dazzling and color-enriched special effects, ultrarealistic worlds, and characters that have more than two colors in them. The end result should be movielike special effects and close-to-photo-realistic art.
This also brings up another lesson I’ve learned. All PC games (with the exception of a few) up to this point have used 256 colors, and it’s not instantly noticeable. The good thing about using 256 colors is that we were pretty much forced to keep our art uniform, and it was nice to have the “auto-continuity.” Now with 16- and 24-bit art, we have to manually keep track and know when to show off our colors and when not to. I’ve found that it’s the details and subtlety that need the extra attention rather than making an “in-your-face” paisley texture.
In Prey, in addition to dealing with textures with a large color depth, those textures are also modulated by our 16-bit radiosity lighting. This has posed some interesting artistic problems for Steve and Scott. In the past, colored and detailed lighting effects were created on the textures themselves. Now, the approach is a little blurry. I’ll let our art guys try to make sense of it.
Lighting textures can be tricky. Many ground and wall textures need to have an even brightness and contrast because they will be tiled. In this case, the game engine then handles the lighting. However, sometimes a light can be drawn onto the texture as a special effect, and the texture can be “lit” by drawing highlights around the light. This is usually done only in cooperation with the mappers, as they need to place lights in the editor to match the light drawn in the texture.
I’ve been told the question I ask most is, “But what does it look like lit?” Once a texture is finished in either Photoshop or Painter, I bring it into Preditor and load it into my handy-dandy test room and throw some lights on it to get the feel for what the player is going to see. Some textures end up catching the light really well while some appear just dead. Then, they’re either fixed or trashed. There’s no other way to tell.
The great thing about colored lighting is the limitless possibilities with the realism that you can create. Of course, when everyone thinks of colored lighting, they think of the really cool bright red siren they can make, or the bright purple black lights that look pretty cool at 100 percent saturation. But the greatest thing for me about colored lighting is the way you can take subtle color differences and make them seem so real. The icy, light blue glare of a fluorescent light in the corner contrasted with the warm glow of a 40-watt lightbulb hanging from the ceiling seems to make a world so much more realistic than the Candyland lights that dominate today. Overall, I think with the introduction of colored lighting in all of the next generation of games, the worlds that mappers create will seem more and more real to the player. But the trick is to make sure the Care Bears would feel right at home.
I generally texture and assign light faces at the same time. This is important, because different light hues work better with different textures. The lighting system in Prey is nothing short of spectacular–the fact that the textures and lighting are all 16-bit adds a depth of realism I could not have imagined. Being able to define any color light, adjust the intensity and assign it to any face, and then within seconds see it in the editor is among my favorite features. What a tremendous time-saver!
The visual details that stream into our eyes make up our primary basis for the belief we have in a game. In Prey, we’re making sure our textures breathe visual life into the geometry, but there’s far more to it than that. The color depth of our textures frees the artists to work with the palettes of their imagination, but often that isn’t enough. Once our environmentalists place textures into a world and then light that world, only then is the recipe complete. And the results are not always what you expect.
Several months back, Scott created a supremely detailed texture, very Gigeresque, that was awash with tendrils and extrusions. We all agreed that it was one of the coolest textures we’d ever seen–but once we tossed it into Preditor and lit it, all of the subtle details of the texture washed away. It was flat, weak, and ugly. About the same time, I asked Scott for a general metal texture with no details that I could slap anywhere (it was before we had precise texture rotation control). Scott angrily whipped out this brown turd of a texture that I reluctantly placed on some objects in Preditor. After lighting, that ugly texture seemed to come alive–it captured the colored light beautifully. We still use this texture all over the place.
The eye is a harsh mistress, but we have no choice but to bow to her decisions, because she is the ultimate arbitrator of our success…in all of our eyes.
Until next time!