ah, now i understand a bit better what you mean.

i think this is a matter of what programming style you prefer. some people like to work with complicated class hierarchies (i don't) and some prefer to keep the oo design simple and work more with classes that don't rely on inheritance that much but simply are aggregates of objects of other classes.

but i still would call both styles object oriented and i think with most engines you can decide yourself how you want to work. i don't have any experience with truevision3d though and i am still a beginner with unity.