1. Apparatus for generating image data, comprising: memory means configured to store data defining a volume comprising a plurality of objects and at least one viewport, memory means configured to store motion data for each of said objects, configuration data for said viewport and instructions, and processing means configured by said instructions to perform the steps of: (a) for each of said objects, defining said motion data in response to user input as a shutter length and a motion path within said volume; (b) for each of said objects, calculating a position along said motion path at an interval of time, wherein said interval is dependent upon said shutter length for said object, and translating said object to said position within said volume; (c) rendering said objects through said viewport to produce a sample; (d) repeating steps (b) and (c) a user-defined number of times at different intervals to produce a number of samples; and (e) blending said samples to generate an image frame wherein each of said objects is independently motion-blurred.