The Synthesis dialog is where you set up motion synthesis for non-bipedal crowd members. It uses three panels to split up the workflow. On the Motion Clips panel, you specify the global object from which the motion clips are to be derived; you also set up the motion clips here. Controls on the State panel let you set up states and link clips to states. The Synthesis panel controls let you blend clips and synthesize the motion for some or all crowd members.
Usage of the Synthesis dialog is closely associated with usage of the ClipState dialog. For a procedure that combines both, see Non-Biped Crowds.