r_lod
From Valve Developer Community
r_lod is a console command that allows overriding distance used in LOD. Higher distance, for example, makes models have less polygons, and textures appear smudged (i.e. less detailed).
Usage
Note:Command parameters are described inside the < and > characters.Syntax: r_lod <integer>.
The default value is "-1" which makes lod compute normally. Setting this to 0 will effectively make every render as if you are close to them while a large value will make everything render as if you are far from them.
Note:Although turning r_lod off gives better visual quality, it also negatively affects your fps rate.