VHS Screen Effect

A full-screen VHS look for Unity's Universal Render Pipeline: red and blue pulled apart, scanlines that drift, a glitch band and posterize.

Contents

File	What it is
Shaders/ScreenVHSEffects.shader	The full-screen shader. It shows up as com.vhs_screen_effect/ScreenVHSEffects in a material's shader menu.
Runtime/UnscaledShaderTimeDriver.cs	Feeds the shader unscaled time, so the effect keeps moving while Time.timeScale is 0. It creates itself before the first scene loads, so you don't add it to anything.
Materials/ScreenVHSEffects_Mat.mat	A subtle preset with a light split and faint scanlines. The glitch band and posterize are off in it.

Requirements

Unity 6000.4 or newer, with the Universal Render Pipeline as the project's render pipeline. The package doesn't list URP as a dependency, so installing it never adds URP to a project that doesn't use it.

Install

In the Package Manager, choose + > Install package from git URL and enter:

https://github.com/fmihalcioiu/unity-vhs-screen-effect.git

Or add this line to Packages/manifest.json:

"com.vhs-screen-effect": "https://github.com/fmihalcioiu/unity-vhs-screen-effect.git"

Setup

Add a Full Screen Pass Renderer Feature to the Universal Renderer Data asset your URP asset uses. Set its Pass Material to ScreenVHSEffects_Mat or to your own material with the shader. Fetch Color Buffer has to be on, because the shader reads the camera image from it.

The packaged material is read-only. To change its values, duplicate it into your Assets folder and use the copy.

Material settings

Setting	What it does
Split Amount	How far the red and blue channels move apart.
Direction	Which way they move.
Scanline Intensity	How dark the scanlines are.
Scanline Density	How many scanlines cover the screen height.
Scanline Drift Speed	How fast the scanlines roll.
Glitch Jitter	How far lines inside the glitch band shift sideways. At 0 the band is off.
Glitch Speed	How fast the band moves through the picture and its lines wobble.
Posterize Levels	How many colour levels each channel keeps.
Posterize Blend	How much of the posterized image is mixed in. At 0 posterize is off.

Unscaled time

The driver sets a global shader vector, _UnscaledTimeParams, from Time.unscaledTime every frame. Its y is the unscaled time in seconds. Your own shaders can read it as well.

Licence

MIT. See LICENSE.md.