One of the ways to increase visual quality in a game beyond “stock” options is so called downsampling. It means that you render the scene in a greater resolution than is your target resolution (conventionally full HD 1920x1080 res). It’s also a good way to utilize your immense processing power while playing older games.
It’s particularly useful when the game engine doesn’t support anti-aliasing; you can emulate AA simply by rendering the scene in a bigger resolution, then downsample it to the target resolution using an appropriate filter. So let’s say you are able to render games in 2160p resolution on 1080p monitor, that’s like a 4x Full Scene AA for you right there. Also it’s usually better than forcing or injecting AA, since such options can cause glitches, or are just non-existent for your game.
This technique also saves the day when your shot is a little bit off your desired direction, or you captured something you didn’t want to be in the final picture, or you realize afterwards the subject is further away as you wanted. In that case, you can crop out your picture all the way up to the target resolution (unless you wanted to use the extra resolution for AA, obviously).
