# Spectrum (Material global keyword)

## Description

Restricts light interaction to those lights with a matching spectrum. Without a matching spectrum, no illumination takes place. In other words, the material is invisible until it’s illuminated by a light with a matching spectrum.

## Usage

spectrum [value]

## Parameters

• [value] - an single digit value that defines the spectrum.

## Notes

Light spectrum is defined within light shaders using the same keyword. For example the following material and light shader use the same spectrum…

textures/hell/pentastic1_spectrum
{
qer_editorimage textures/hell/pentastic1.tga
DECAL_MACRO
nonsolid
noimpact
twoSided
translucent
spectrum 1
{
blend   diffusemap
map textures/hell/pentastic1.tga

}

}

lights/biground1_snd_spectrum
{
spectrum 1
{
forceHighQuality
map     lights/biground1.tga
red             sound * Parm0
green           sound * Parm1
blue            sound * Parm2
zeroClamp
}
}