Simple question:

Is there a way to tag a model so that it isn't rendered at low graphics settings?

I'm thinking about models that are entirely cosmetic — no impact on gameplay, but they make the map look good. Weeds, for instance.

Not exactly, but the gamecode supports level of detail for the entity misc_gamemodel with the following keys :

Code: Select all

lodmodel1: file name of the first LOD model replacement
lodmodel2: file name of the second LOD model replacement
loddistance1: distance after which to show the first LOD model replacement (default: 1000)
loddistance2: distance after which to show the second LOD model replacement (default: 2000)

Customization of LOD distance are not implemented client side yet, but low poly versions of your models will already improve performance a lot.