The AMAS defines machinima as "animated filmmaking within a real-time virtual 3-D environment". In other 3-D animation methods, creators can control every frame and nuance of their characters but, in turn, must consider issues such as key frames and in-betweening. Machinima creators leave many rendering details to their host environments, but may thus inherit those environments' limitations. Because game animations focus on dramatic rather than casual actions, the range of character emotions is often limited. 