This repository hosts a shader for Unity3D whose main goal is to facilitate the creation of neon-like signs, conveyor belts and basically whatever based on scrolling textures
Right now, scanlines appearance (other than speed) can only be customized by tweaking one width value, which affects both the "on" width and the "off" width but it is not possible to specify those two values separately.
Possible ways to achieve this:
Replace the sine wave with a square wave generator function and tweak the duty cycle. This way we would lose the ability to make scanlines "soft" tho.
Implement a duty cycle on the sine wave itself somehow, maybe by establishing a threshold value [0...1] and saturating / ceiling the sine wave from that threshold upwards.