Animable properties are those which can be altered over time by a predefined keyframe sequence. They may be set directly, or they may be modified from their existing state (common if multiple animations are expected to apply at once). Implementors of this interface are expected to override the 'setValue', 'setCurrentStateAsBaseValue' and 'ApplyDeltaValue' methods appropriate to the type in question, and to initialise the type. AnimableValue instances are accessible through any class which extends AnimableObject in order to expose it's animable properties. This class is an instance of the Adapter pattern, since it generalises access to a particular property. Whilst it could have been templated such that the type which was being referenced was compiled in, this would make it more difficult to aggregated generically, and since animations are often comprised of multiple properties it helps to be able to deal with all values through a single class.