The most interesting feature of GPU particles, aside from their efficiency, is vector fields. A vector field is a uniform grid of vectors that influences the motion of particles. Vector fields are placed in the world as Actors and can be translated, rotated, and scaled like any other Actor. They are dynamic and may be moved at any time.
A field may also be placed within Cascade, limiting its influence to the emitter with which it is associated. When a particle enters the bounds of the vector field its motion will be influenced by it and when a particle leaves the bounds the influence of the field will fade out.