As Cities: Skylines 2 players try to figure out what they can do to improve performance, they're coming up with some pretty wild theories about what's wrong - including the idea that the game is rendering every citizen's individual teeth. Developer Colossal Order has addressed that claim, and while it's not exactly wrong, it's not the full truth either.
Most 3D games feature some sort of 'level of detail' scaling, which ensures that characters and objects that are further away from the camera will be rendered in less detail than those that you're seeing up close. The various gradations of those models are often referred to as 'LODs,' and good LOD management is an essential component of maintaining a solid balance between graphical fidelity and solid frame rates.
That's why many players were shocked by a post from Reddit user Hexcoder0 revealing that "the game DOES render individual teeth with no LOD as far as I can tell." Hexcoder0 was able to check in on what the graphics card renders while the game is running and found that, yeah, the character models for the individual citizens wandering around on the streets do indeed appear to have individually rendered teeth.
This sparked a whole tangential debate about whether mods could turn these citizens into stick figures, and some players worried that the game's lifepath system - which tracks citizens from birth into adulthood and old age - might make reducing their detail impossible.
In response to this whole teeth and lifepath thing, developer Colossal Order said in a statement that the "citizen lifepath feature does not tie to citizen geometry and does not affect the performance figures of the characters. We know the characters require further work, as they are currently missing their LODs which affect some parts of performance. We are working on bringing these to the game along general LODs improvements across all game assets. Characters feature a lot of details that, while seemingly unnecessary now, will become relevant in the future of the project."
That doesn't exactly debunk the idea that overly detailed teeth could negatively affect performance, but it does suggest that it's not the lifepath system that's busting the game's frame rates. The bigger thing to bear in mind here is that while some LODs may be missing by the studio's own admission, that doesn't mean the game is rendering tens of thousands of toothed-up citizens at all times - individual citizens still disappear from view when the camera is at a sufficient distance, and the frame rates still struggle even when you're looking at a big town from an extremely wide angle.
A Cities: Skylines 2 patch has at least given us a good start toward improved performance, though more work is still needed. At least we all get to enjoy a few memes about the teeth in the meantime.
Check out the best city-building games out there - there's one about beavers, and that has to have more teeth than Cities: Skylines 2.