Console Commands to Reduce Texture and Model Resolutions?

[Xia]

I've been looking for commands to manually reduce the game's texture and model resolutions, seeing that changing them in the options settings gives me all kinds of crazy error messages.

Could someone tell me if there are specific console commands to reduce these settings to a minimum?

[gamezombie]

mat_picmip for textures (it only goes upto 10) the higher the number the lower res the textures will be