Game Effects

Games are full of visual effects-probably even more than you realize. These effects are important not just as eye candy but also for giving the player clues and information about what is happening in the game world. These effects also add a great deal to the level of immersion that a player will experience in a game. For example, in some games you can shoot at a wall and nothing will happen-so you wonder, did a bullet come out of your gun? In another you can shoot a wall and a few pixels may fl y from the point of impact; how satisfying is that? Shoot a gun at a wall in a recent game of any quality and you will see a hole or abrasion on the wall, a small shower of debris fl y from the point of impact, and a puff of dust dissipate into the air. Typically, if you shoot at any surface in a game-wood, metal, concrete, and their variations-you will see and hear a different effect for each surface. Effects also include the glow around a candle, light shafts from a window, even raindrops-and a whole lot more. The assets for these effects are fairly easy to create. Actually, asset creation is the easy part of creating effects in a relative sense. It does take work to create the art and it must look good, but the systems that run the effects can still be complex and challenging to work with. There are generally three types of effects for which you will create assets:

Most effects are based on a fairly simple texture and mesh set, and the texture and mesh of the static effect don’t move. Effects such as the light beams streaming from the windows in a warehouse and fantasy settings and the glow around candles in fantasy settings are static effects. Some of the most common static effects are the marks left on a wall after the impact of a bullet, like those in the opening image of this chapter. We’ll create all the various impact marks on each of the different surfaces in this chapter. See Figure 9.1 for an illustration of the bullet-hole image (with alpha) mapped to a twotriangle polygon to create the decal and how it looks when placed in the world. Effects like the bullet holes are called decals because they are displayed like a decal on a surface in the game world.