Developer Quest Magazine picks Aaron Leiby's (SFX programmer at Legend) brain on general Wheel of Time development stuff and, of course, eye candy:

I also like to think of myself as the Special Effects programmer for WoT. I've added a few of the cooler features (IMHO) to WoT. Such features include weather effects like the rain we showed off at E3, and a generalized particle system that we use extensively throughout WoT -- from the ter'angreal effects to campfires to healing zones. I also added the ability to leave scorchmarks and bloodsplatters on surfaces throughout the levels. This increases the player's immersion level by making them feel like they're really affecting the level around them -- many times, it's the simple things that make the biggest impact. Such effects usually stem from one of the level designers coming down to my office and saying, "you know what would be cool...", and shortly thereafter, its in the game. I provide the toys, and the level designers use them in their levels.