I finally got a new computer to be able to run The Sims 3, but after installing it I found a strange issue. The "default" (as in, unpainted) terrain texture looks extremely blurry, like it's not loading properly. Everything else looks fine, and terrain paint looks normal, it's just the unpainted default that's looking weird. See screenshots below:

https://imgur.com/a/OWxwbBg

Any idea what might be causing this? I haven't installed CC yet and the only mod I have at the moment is Overwatch (figured it wasn't worth starting to download mods and CC before figuring out what's wrong with the game).

I did previously try to download a texture replacement mod - can't recall which one as this was a couple of weeks ago - but that didn't help so I uninstalled the whole game and tried reinstalling today.

Specs:
OS: Winodws 11 Home
Processor: Intel(R) Core(TM) i5-14600KF 3.50 GHz
RAM: 16.0 GB (15.8 GB usable)
GPU: NVIDIA GeForce RTX 4060 Ti

I managed to solve it and figured I'd reply to myself with the solution in case anyone else with the same issue finds this is the future.

I came across this 10 year old thread about the same issue, which suggested enabling Advanced Rendering in the options. I did, and now the terrain looks normal! So if anyone is experiencing this blurry terrain glitch, try enabling Advanced Rendering. The person in the thread also tried something else which seemed to work too so that's a further option I guess, but this in-game setting was enough to fix it for me.