The GenEffects function is used to create one or more Effect objects. An Effect object stores an effect type and a set of parameter values to control that Effect. In order to use an Effect it must be attached to an Auxiliary Effect Slot object.

After creation an Effect has no type (EfxEffectType.Null), so before it can be used to store a set of parameters, the application must specify what type of effect should be stored in the object, using Effect() with EfxEffecti.