Controls the distance at which objects are rendered and the amount of detailed rendered. The user interface, under Options, Graphics and Audio, allows this to be changed via a slider. The slider goes from 50% (0.5) and 200% (2.0). The /vis_scale command allows you to increase the scale up to 400% (4.0). Any scale higher than 4.0 is rendered as 4.0, and any number lower than 0.5 is rendered as 0.5.