Can you benefit from downsampling if the textures aren't as high of a resolution?

[VG Docs]

Minor note: I don't know where this subject would belong so I just put it in Off topic.

Preamble

I was recently looking at the comments of a video of a guy who played GTA V rendering at (effectively) 10k resolution through downsampling to a 5k resolution. There are a few comments going over how it would be pointless to go that high of a resolution due to the textures in GTA V not being that high (I don't know the validity of this claim and I don't know the resolution of the textures for GTA V).

 

Question

 

• Can you benefit from downsampling, or a higher resolution than what the game's textures are?

 

My First Guess (w/ Supported Theory)

My first guess (as an emulation nut) is definitely. In emulation, if you were to bump up a PS1 game's resolution (such as the common 320x240 resolution of the day) beyond its native resolution (like 1280x960)- the difference is huge. While the textures themselves may or may not have any difference, it seems like everything else does. However, is having 10k downsampled to 5k in a game with noticeable lower resolution textures going to make a noticeable difference from whatever the native resolution of their textures is? I'd think so but, while I'm very familiar with certain parts of technology, I don't know much about game design this detailed.

Second Guess (Shot in the dark?)

I thought about this subject a little more and thought about pixels vs texels. Keep in mind that this is just my own unsupported hypothesis with very little research done (and I have no idea of how accurate it could be) but this is how I look at it:

Pixels are of screen space, texels are of texture space. Most things (outside of textures) are made up of pixels? Lighting, Shadows, AO, AA, Particles, etc would all be made up of pixels, right? In fact, outside of textures and texture filtering, what uses texels instead of pixels? Geometry- or does that use pixels too?

 

Conclusion?: Thus (assuming this is correct info, which I have no idea if it is or not), we can assume that GTA V at 10k downsampled to 5k would likely be noticeably better looking than if the resolution of the game itself was the same as the textures. Reasoning: While the textures and texture filtering may see no benefit, almost everything else would - shadows, lighting, particles, ao, edges of geometry, and AA (which is the only one that most people know to be a benefit of downsampling).

Although I'm completely in the dark as to whether there would be any benefit when talking about the following - geometry itself (not just the edges), animation (wouldn't that only benefit from higher frame rate?), physics

 

Keep in mind that this guess is entirely speculative and by someone who knows nothing about this kind of tech. If I'm wrong though, I'd like to know what's wrong as well as what the correct information would be.

[KingKeith55]

You can get an anti-aliasing effect no matter what, but it's not worth it really unless you have a really good PC or the game is really easy to run.

[VG Docs]

/sigh

Completely ignores entire post and says something more obvious

[PlayStation 2]

I think you could, especially if a game doesn't allow for anti-aliasing but allows you to run it at arbitrary resolutions for whatever reason. It's like running a game through an emulator at a much higher resolution than your monitor's native resolution; the textures won't improve by themselves but you're going to get the textures (and every other asset as a matter of fact) displayed a little cleaner. Let's take Team Fortress 2 as an example:

It's a game meant to run at 720p, or 1024x768. It's running at four times that resolution, and notice that while the textures aren't that high a resolution, they do look sharper. Take this down to 1024x768 and not only would rough edges smooth out very fast, stuff in general would look cleaner, and you get the benefit of screenshot porn.