Game Development Reference
the lights back on and blow out the candles. Seeing that is likely to evoke an
emotion in the player as well. Even if the AI can't handle candles, the emotional
payloads delivered by turning the lights down and then back up compared to the
low cost of having an AI that knows the difference between business and pleasure
makes a strong case for AI-controllable lighting. An FSM might be all that is
needed to model the emotional state of the AI.
The level of AI devoted to lighting control varies from the simple controls
described earlier to the baked-into-the-game control seen in Thief 3, Deadly
Shadows [Spector04]. AI-controlled dynamic lighting shows great promise for a
more engaging player experience, especially with non-gamers and casual gamers.
The ALVA lighting control system given in [El-Nasr09] improved player per-
formance and lowered player frustration.
Unlike clothing, the additional asset cost for AI-controlled lighting is quite low.
Light fixtures and light switches would already be in the level. Compared to
outfits, soft lighting is cheap. Lighting is just as visual as clothing selection.
Virtual characters are not the only things in a level that wear ''clothing.'' As noted
by Chris Hecker when he posited that one day there would be a Photoshop of AI ,
graphics rendering in games is done via texture-mapped triangles [Hecker08].
For those unfamiliar with graphics, a texture is an image that is applied to the
geometric skin of an object, and that skin is built using triangles. A flat wooden
door and a flat metal door might share the same geometric skin, but they use
different textures to make that skin look like wood or metal. The graphics system
can switch between those skins easily after an artist has created them both and
they are loaded into the system. This takes us down the same rabbit hole into
Wonderland that the rest of the chapter falls into. If it can be changed, that
change will need control, and why not have the AI manage some of it?
This one really could take us to Wonderland. We start out being able to change
the color of the leaves, which happens in the real world, and wind up wherever
the crazed minds of artists and designers can take us. Imagine a world in which an
unlimited supply of spray paint (including transparent) and wallpaper can be
applied instantly to anything and everything, changing every time you blink or
close your eyes. Shapes remain constant, but appearances change instantly.
Luckily, we do not have to go all the way into this Wonderland. More subtle and
skilled artists could take us partway there, to a world where things change when we