Originally Posted by
AriaEnia
Isn't that what they do when rendering? Making circle things to become octagonal to preserve memory for lower settings? Removing anti-aliasing for performance is also the cause of this.
Hovering grass probably because there's many grasses there in higher settings so the hovering grass is actually on the middle of the grasses around it to give them some height, and when they reduce for them for lower settings, it becomes visible.
Edit: but then again, I'm not an expert on this so, it's based from what I observe when I used to play PC games, changing many GFX settings lowering them to make the games run smoother.