The first thing to do is to analyse if what you want to realise is to be considered just a technical job or could be defined as an intellectual work. In the first case, or rather if your work consists only in the reproduction of certain data in a certain format and animate them by using an appropriate programme, without you doing any creative work, then there is no problem of interpretation, as you would only carry out a task, you would be paid out for that and could not pretend anything else. If, on the other hand, the work is a creative one, coming from a basic drawing or from a simple idea you develop three-dimensional graphic or animations that can be considered intellectual works, then the matter changes. In such case, the copyright goes to the author, but if the work is made on commission and only for that purpose, then the only right owing to the author is the “moral” one and not the financial one. This means that the maker of the work would always have to be indicated as the author, but could not claim any extra financial compensation for the use that the commissioner would make of the work. The only alternative to modify this aspect of interests, is to put in writing, at the time of the commission, that the copyright would have to be managed in a certain way rather than in another, perhaps reserving the purpose of the work in other ways. Bear in mind, though, that in case of use of photos or drawings of third parties, it is not possible to expand on them without their consent, therefore this aspect too would have to be evaluated every time.