FUNDAMENTALS OF GAME DESIGN, SECOND EDITION
IDENTIFYING ACTIVE OBJECTS
With the advent of 3D-modeled worlds and powerful physics engines, just about every object that's not part of the scenery can, theoretically, be manipulated or picked up by the avatar. However, most objects in a scene don't actually play a role in the story; they're just part of the set decoration. The player needs a way of recognizing the active objects in a particular location. Text adventures used to print a list of active objects. Graphic adventures typically use one of four mechanisms:
■ Hunt and click. Active objects don't look any different from anything else; the player simply has to click everything in the scene to see which parts are active.
This makes the scene look realistic, but the player may find it annoying, especially if some active objects are small or partially hidden. Designers have generally abandoned this method in favor of the following ones.
■ Permanently highlighted objects. The active objects in a scene appear permanently highlighted to make them stand out from the background. You can do this in a number of ways; for example, make them slightly brighter than the rest of the scene or surround them by a line of light or dark pixels. The moment the scene appears on the screen, the player can tell which objects are active. It's convenient, if artificial. Children's games often use this method.
■ Dynamically highlighted objects. The active objects in a scene normally look like part of the background but appear highlighted when the mouse cursor passes over them. You can, for example, change the shape of the mouse cursor, have the object light up, or have the object's name appear momentarily. It still requires the player to do some hunting, but hunting is much easier than hunting and clicking; a quick wave of the cursor tells the player if there's an active object nearby.
■ Focus-of-attention highlighting. This mechanism is typically used with handheld controllers when the player doesn't have a cursor. As the avatar moves around, the focus of his attention changes depending on the direction he is looking. Whatever active object lies directly in front of him commands the focus of his attention and appears highlighted. When he turns away, this highlighting disappears. If two active objects are close together, however, the player may find it tricky to point the avatar in exactly the right direction to put the focus of attention on the desired object.
