Systems and methods are described for animating 3D characters using synthetic motion data generated by generative models in response to a high level description of a desired sequence of motion provided by an animator. In a number of embodiments, an 
animation system is accessible via a 
server system that utilizes the ability of generative models to generate synthetic motion data across a continuum to enable multiple animators to effectively reuse the same set of previously recorded 
motion capture data to produce a wide variety of desired 
animation sequences. In several embodiments, an animator can upload a custom model of a 3D character and the synthetic motion data generated by the 
generative model is retargeted to animate the custom 3D character. One embodiment of the invention includes a 
server system configured to communicate with a 
database containing motion data including repeated sequences of motion, where the differences between the repeated sequences of motion are described using at least one high level characteristic. In addition, the 
server system is connected to a communication network, the 
server system is configured to 
train a 
generative model using the motion data, the 
server system is configured to generate a 
user interface that is accessible via the communication network, the 
server system is configured to receive a high level description of a desired sequence of motion via the 
user interface, the server system is configured to use the 
generative model to generate synthetic motion data based on the high level description of the desired sequence of motion, and wherein the server system is configured to transmit a 
stream via the communication network including information that can be used to display a 3D character animated using the synthetic motion data.