Light, without it we wouldn't be able to see. And so it is in videogames. Lights are fundamental, every game have some sort of light, if ever so simple. In todays 3D games, there need to be some way to compute lighting data within 3D space, as volumetricaly most of the light eixst outside of a 2D face where the light is visible. How does the lighting really work in the GoldSrc engine? Does anyone know except for Valve themselves?
This is my theory on how it works: Of course I can't be sure... But anyone should know.