⚠️ NOTE: This repository was deprecated as all future development of it happens in the realism-effects repository. This version does not work anymore with the latest three.js version. If you'd like to use the advanced SSR implementation, follow the readme of the new SSR repository.

three.js Screen Space Reflections

Implements performant Screen Space Reflections in three.js.

Demos

• Basic

• Animated Background

react-three-fiber demos:

• Rover

• three.js journey scene

Usage

If you are using react-three-fiber, you can also use the SSR component from react-postprocessing. Check out the react-three-fiber demos to see how it's used there.

Basic usage:

This effect uses postprocessing.js. If you don't have it installed, install it like so:

npm i postprocessing

Then install this effect by running:

npm i screen-space-reflections

Then add it to your code like so:

import { SSREffect } from "screen-space-reflections"
import * as POSTPROCESSING from "postprocessing"

const composer = new POSTPROCESSING.EffectComposer(renderer)

const ssrEffect = new SSREffect(scene, camera, options?)

const ssrPass = new POSTPROCESSING.EffectPass(camera, ssrEffect)

composer.addPass(ssrPass)

Options

const options = {
	intensity: 1,
	exponent: 1,
	distance: 10,
	fade: 0,
	roughnessFade: 1,
	thickness: 10,
	ior: 1.45,
	maxRoughness: 1,
	maxDepthDifference: 10,
	blend: 0.9,
	correction: 1,
	correctionRadius: 1,
	blur: 0.5,
	blurKernel: 1,
	blurSharpness: 10,
	jitter: 0,
	jitterRoughness: 0,
	steps: 20,
	refineSteps: 5,
	missedRays: true,
	useNormalMap: true,
	useRoughnessMap: true,
	resolutionScale: 1,
	velocityResolutionScale: 1
}

❗ Highly recommended: Use a GUI to tweak the options

Since the right options for an SSR effect depend a lot on the scene, it can happen that you don't seem to have an effect at all in your scene when you use the SSR effect for the first time in it without any configuration. This can have multiple causes such as `` being way too low for your scene for example. So to find out which SSR options are right for your scene, you should use a GUI to find the right values easily. The example already comes with a simple one-file GUI SSRDebugGUI.js that you can use in your project like so:

• First install the npm package of the module used for the GUI:

npm i tweakpane

• then just copy the SSRDebugGUI.js to your project and initialize it like so in your scene:

import { SSRDebugGUI } from "./SSRDebugGUI"

const gui = new SSRDebugGUI(ssrEffect, options)

That's it, you should now have the GUI you can see in the example scene. The options parameter is optional for the SSRDebugGUI and will default to the default options if no options parameter is given.

Run Locally

If you'd like to test this project and run it locally, run these commands:

git clone https://github.com/0beqz/screen-space-reflections
cd screen-space-reflections/example
npm i --force
npm run dev

Features

• Temporal Reprojection to re-use the last frames and thus reduce noise
• Accumulative sampling to reduce noise over time
• Jittering and blurring reflections to approximate rough reflections
• Using three.js' WebGLMultipleRenderTarget (WebGL2 only) to improve performance when rendering scene normals, depth and roughness
• Early out cases to compute only possible reflections and boost performance
• Box Blur to reduce noise
• Feature to generate box-projected env maps as a fallback to reduce artifacts

Tips

Expand to view tips

Getting rid of artifacts

If you are getting artifacts, for example:

Then try the following:

• increase thickness
• increase maxDepthDifference
• decrease ``and increasesteps if reflections are cutting off now
• increase refineSteps

Keep in mind that increasing these values will have an impact on performance.

Hiding missing reflections

Since SSR only works with screen-space information, there'll be artifacts when there's no scene information for a reflection ray. This usually happens when another objects occludes a reflecting object behind it.
To make missing reflections less apparent, use an env-map that can then be used as a fallback when there is no reflection. Ideally use a box-projected env-map.

Here are two implementations for three.js and react-three-fiber:

• Gist to include box-projected env-maps in three.js
• useBoxProjectedEnv in react-three-fiber
  

Getting updated reflections for animated materials

By default, the SSR effect won't really update reflections if the camera is not moving and no mesh in the view is moving. However, it will check if a mesh's material's map is a VideoTexture and will keep its reflections updated each frame. If your material is not using a VideoTexture but is still animated (e.g. it's a custom animated shader material), then you can get updated reflections for it by setting mesh.material.userData.needsUpdatedReflections = true. This will make the SSR effect recalculate its reflections each frame.

Server Side Rendering and window being undefined

If you are using Server Side Rendering and don't have access to the window object then the SSR effect won't be able to set the correct width and height for its passes. So once you have access to the window object, set the correct width and height of the SSR effect using:

ssrEffect.setSize(window.innerWidth, window.innerHeight)

Sponsoring

If the project is useful for you and you'd like to sponsor my work:

Credits

• SSR code: Screen Space Reflections on Epsilon Engine

• Edge fade for SSR: kode80

• Velocity Shader: three.js sandbox

• Box Blur filter: glfx.js

• Video texture: Uzunov Rostislav

Resources

Screen Space Reflections in general

• Rendering view dependent reflections using the graphics card

• Screen Space Reflections in Unity 5

• Screen Space Glossy Reflections

• Screen Space Reflection (SSR)

• Approximating ray traced reflections using screenspace data

• Screen Space Reflection Techniques

• Shiny Pixels and Beyond: Real-Time Raytracing at SEED

• DD2018: Tomasz Stachowiak - Stochastic all the things: raytracing in hybrid real-time rendering (YouTube)

• Real-Time Reflections in Mafia III and Beyond

Temporal Reprojection

• Temporal Reprojection Anti-Aliasing in INSIDE

• Reprojecting Reflections

• Temporal AA (Unreal Engine 4)

• Temporally Reliable Motion Vectors for Real-time Ray Tracing

• Temporal AA and the quest for the Holy Trail

• Visibility TAA and Upsampling with Subsample History

• Temporal Anti Aliasing – Step by Step

• Filmic SMAA: Sharp Morphological and Temporal Antialiasing