The attributes of an entity that are used to infer its bounds. There are three general use cases for inferred attributes - 1) things with a definite, asset-based size like sprites and models. 2) things with a size that is only sensibly defined by users like emitters and effects. 3) things where size won't matter in any case like sky boxes and configuration stand-ins. TODO: see if we can refactor this type to make its representation and algo more understandable.