1. A graphical user interface comprising: an editing window; means for enabling a user to specify in the editing window one or more transformation hierarchies including one or more transformations, wherein a transformation provides transformation data as an output; means for enabling a user to specify in the editing window and one or more effects trees, wherein at least one effect in the effect tree has one or more inputs for receiving transformation data and has a local transformation specification that is combined with the received transformation data; and means for enabling a user to connect an output of a transformation to an input of an effect for receiving the transformation data.