With reference to what Kate Fernie pointed out in the 3D content in Europeana task force Report (pp. 28-29), the main problem with LIDO with regard to 3D is that there is no direct relation between a certain resource representing the object and a certain event it was involved in. So it might be worth considering adding a relatedResourceSet (including a resource ID) in the EventSet and/or a relatedEventSet in the resourceSet. It would not only help with 3D content, but also with ex. conservation-related events/resources (before-after images of a conservation event) etc. It would also be very interesting to know what you are planning to do with regard to updating the LIDO vocabulary.