Godot Dithering Shader

A screen-space viewport shader for Godot (GLES2 or GLES3), replicating the ordered dithering effect of older displays/image colour palettes.

(preview images have 4 colours per channel)

Supports any amount of colours, custom dither depths, and custom dithering patterns (Bayer matrices, blue noise, etc.)

Download preview demos here (Windows, Mac, Linux)

Basic setup

Following the process laid out in the custom post-processing section of the Godot docs:

• Download "Godot Dithering Shader.shader" from this repo and move to your project folder
• Render target scene to Viewport contained inside ViewportContainer node
• Create a new ShaderMaterial in the ViewportContainer and load the shader into it
• Add your chosen values/pattern to the shader parameters

Make sure to disable texture filtering on your dithering pattern!

Limitations

• Requires a dithering texture locked to viewport size (e.g. 640x480 viewport requires 640x480 dithering pattern texture)

Issues

• if using GLSL2, will not work in HTML5 export (requires dynamic loops)
• Hangs sometimes when playing project from editor (doesn't seem to affect exports)

Demo scene credits

• PM5644 test image created by RTFMASAP on Wikimedia Commons (https://commons.wikimedia.org/wiki/File:PM5644-1920x1080.gif), under CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0/deed.en)