Well, i finally got around to examine the issue with megatextures and idtech5. And it is true what they say about megatextures being great for scenery but wortheless for close up views. In wolfenstein new order the environment looks great. But as soon as one zooms in at for example the walls, it just looks horrible out focus and unsharp. Like a dx7 game. With more common techniques, the textures that are used to build the walls for example are replaced with textures that have more detail the closer one comes to a wall. I wonder how they solved this with idtech 6.
And the jagged edges are everywhere in the game, anti-aliasing is not present and at least not available as a setting in the game. Maybe through the command console, have not tried that.
That has nothing to do with the virtual texture tech. The Rage artists wanted to make a game without any obvious texture repetition. Problem with that is the game would be huge unless they sacrificed the quality of individual textures.
There's nothing inherent to "megatextures" that makes them low res. In fact, the technology essentially removes limits on texture resolution entirely (assuming you have enough storage space), since the game only loads in the needed texels for what's on screen. So texture memory use is basically determined by resolution.
I think with doom they re-used more textures cause it kind of fits the setting. So, they had more room for everything to be higher quality.