NBA JAM Designer Diary #3

Brandon Fish
NBA JAM Producer
Acclaim Studios Austin

Introduction
Looker. Jar of eye candy. Jaw-dropping, mouthwatering, stunning knockout. There are many ways to describe a game with good graphics. What defines those graphics has changed over time. The things that amazed us two years ago wouldn't even get a second look today. It's difficult to keep up when the graphics bar is always being raised, but as a developer you have to plan ahead for it. The way a game looks is the first thing that will grab the player, whether it's with a screenshot, the packaging, or watching someone else play. If it doesn't look good, nobody is going to give it a chance. In this third entry in the NBA Jam Designer Diary, we will give you a sneak peek at some of our early concepts, show you some of our special effects, and tell you how we get it all working together at a crisp 60 frames per second.

The Jam Art Style
It's difficult to decide upon an art style, and even more difficult to put it into words. The focus of the game is on the players on the court, so the way they look can dictate the way the rest of the artwork comes together. Our first step in developing our style was to sketch out what our players would look like. In many ways, NBA Jam is a caricature of the NBA game in real life. We made a conscious effort to remain true to the style and feel of the original game. We examined three approaches to the player models: realistically proportioned, completely exaggerated, and somewhere in between. There were some concerns that the completely exaggerated style might not translate well to an onscreen model. We ended up deciding on using somewhat exaggerated proportions but using realistic textures.

Player Details and Player Models Using those initial concepts, we built our first player models. We knew that we were going to have a fast engine, so the artists were given a large 3,500-polygon count to work with. When you combine that with the shadows and reflections, that's nearly 5,000 polys to render each player! A lot of other sports games simply slap a slightly modified texture onto a generic head model to create the vast number of player likenesses. One of the best parts about the NBA is the individuality of each of the players, and we wanted to preserve that in NBA Jam. We chose to take approximately 1,000 of the allotted polygons and apply them to the player heads. Each and every one has been individually modeled and textured so it is completely unique. When these unique heads are combined with our four different body types, individual tattoos, and player equipment, it's very easy to recognize your favorite player on the court. The players have been tweaked and modified during the entire project. For example, we had to tweak the size of some of the skinnier players, because they would almost disappear when the camera was farther away from the action. The final results of all the fine-tuning look great, though. Each character retains the flavor of his real-life counterpart but is just stylized enough to fit the NBA Jam motif.

Player Animation Of course, it's all well and good to have great-looking models, but if they don't move, they aren't going to impress anybody. With the 700-plus moves we were planning on using, we knew that we were going to have to use motion capture to generate almost all our animation. We even enlisted the help of some guys from Slam Ball to do a lot of the trampoline work on some of the superhuman moves.

In addition to normal animations, we also use several techniques to make things look better. We use animation blending to move between animations so you never see players pop from one to another. We also have a morph system for the heads so we can apply any facial expression we want. You can see it mostly in replays, but the players will also flash you a smile when you select them for your starting lineup.

We also have an inverse kinematics system so players will reach for the ball and dunk it appropriately. A proper physics system then takes over as the rim and goal structure bend down with the force of the player. It all looks great when it comes together and makes for some spectacular-looking slams.

Special Effects
What would NBA Jam be without special effects? For one thing, you wouldn't have the classic "on fire" mechanic. Going into this project, we knew that we were going to have to build a powerful particle system that would handle all the fire, smoke, streaks, and other effects that we needed without compromising our frame rate. We built a new system from scratch, including a robust editor that allows our artists to create the particles quickly and gives them a preview of what they are building before it goes into the game. In addition to all the particle effects, we also have special filters for our replays and the NBA legends tournament. When you go back to the old-time era of basketball, we try to match the old broadcast style with a black-and-white filter. It turned out even cooler than we even anticipated and helps give the NBA Legends Tournament its own feel.

No Compromises
Developing a game for multiple platforms at the same time always has its challenges. Something that works really well on one console might not work at all on another. Often you are forced into the lowest common denominator across all systems, and nothing is as good as it could be if you had focused on only one. Our goal is to make the game look as good as possible on both the Xbox and PS2 without any compromises. This is a game that demands 60 frames per second at all times, so it wasn't going to be easy. In the end, except for some minor differences in display, both versions look and play identically. If there was a cool thing we were doing on one platform, we found a way to get it done on the other. We even created technology to have full 3D crowd characters animating and following the action on both platforms.

Putting it All Together
When you put all the pieces together--the players, the animations, the special effects, and the stadiums and outdoor arenas--you come out with a fantastic-looking game. Even though the screenshots look great, it looks even better in motion. In the next diary, we'll flip to the other main component of video games, the gameplay. We'll get into all the NBA Jam game mechanics, go through our different modes, and help get you inside the heads of our designers. Until then, enjoy the mind-blowing, spine-tingling, eye-popping screenshots!