$reflectivity

$reflectivity overrides a VTF file's embedded reflectivity value. It tells VRAD how much light should be bounced off the material, without affecting how much it receives.

$reflectivity only affects static light.

Usage

$reflectivity "[.5 .5 .5]"            //To bounce 50% of received light
$reflectivity "[0.75 0.75 0.75]"      //To bounce 75% of received light

The value is a material vector, representing a RGB vec color value.

Different reflectivity values.

[.25 .25 .75] to add an extreme blue tint on the reflected light

Source: https://developer.valvesoftware.com/wiki/$reflectivity Reference: https://nodraw.net/2011/02/reflectivity/