---
draft: false
title: Screen Space God Rays
tags:
  - graphics
---

While thinking about graphical improvements to [[01.far-reaches|The Far Reaches]], I landed on the decision to invest some time into environmental weather effects like rain, snow, clouds, etc. I was deeply inspired by [t3ssel8r's video](https://www.youtube.com/watch?v=fSNdZ82I-eQ) on god rays (and much of his other stuff) and decided to take a crack at it myself. Before we begin let's break this down to understand what we're talking about here starting with *god rays*. 

## God Rays

You've seen these before likely both in real life and in video games.

> [!caption|center] 
> ![[crepuscular_rays_real.png]]
"God Rays"

The scientific term for this phenomenon is called **crepuscular rays** and the term in the graphics programming world is **volumetric light scattering**. These effects are caused by clouds or other objects and give the impression of "shafts" of light emitting from the sun. Essentially the shadows from the clouds create shadowed and un-shadowed regions of the atmosphere where light is being scattered and the contrast between these regions gives the effect of "shafts" of light emerging from the sun.

## Implementation