They did have the means to make three-dimensional replicas, and some sculptors, with their plaster casts of statuary, would no doubt have been able to recognize true copies. It is not clear, however, that many of their patrons could have done so. For example, only those who had actually traveled to Knidos, an island just off the Aegean coast of Turkey, and seen Praxiteles's marble Aphrodite would have been able to distinguish between a meticulously accurate copy and a work that just resembled her. Nor, finally, is there any reason to assume that the few Romans who could recognize a faithful copy of an original ancient masterpiece would have preferred one. The preferences of Roman connoisseurs seem to have been quite different.
All Roman art depends to some extent on Greek art.
The subjects, the styles and the media of Roman artists were all derived from Greek precedents. In all the arts apart from sculpture, however, there are very few exact copies. What we see instead are creative adaptations. Roman architecture, for instance, is closely patterned on Greek architecture. Roman temples are inconceivable without their Greek predecessors, but they remain distinctly Roman.