Sark's Carrier: Look carefully and you'll see the wireframes around the ship

Wireframes are the lines that make up the shapes you see in a geometric object, which pretty much form a wire frame, as the name suggests. Early videogames like Novagen's Mercenary exclusively used wireframes to represent the 3D world you explored there, as a substitute for the real world that the imagination would conjure up. However, in Tron, Sark's Carrier's CGI shows faint but visible wireframes that were most likely leftovers from the rendering process, most notably in the briefing scene where Sark tells Flynn and the other new recruits about the identity discs, etc, and in the scene where the Carrier chases the Solar Sailer.