The Rocket sample, recorded live in-engine: a lander threads a dark cave while its thruster flame and glowing red, purple, and green crystals light the terrain and cast moving shadows in real time.

Light2D is a GPU-based dynamic 2D lighting package for Unity with a distinctive look: colored per-channel light transmission through obstacles, soft ambient bounce, and collider-free occlusion authored straight from your sprites, meshes, and tiles. Lights and obstacles move freely at runtime and need no physics colliders. One package drives both the Built-in Render Pipeline and URP 17.3+ on Unity 6000.3 or newer, under the MIT license.

Showcase

All of these are live in-engine recordings from the bundled Examples sample:

Colored point lights wash floating sprite obstacles, and each block casts its own colored shadow.	Bat-shaped occluders fly across a white light, sweeping large soft shadows over the wall.
A point light cycles through hues, tinting a cluster of block obstacles and the shadows they cast.	A single white light sweeps drifting cube obstacles, each catching the light and casting a soft shadow.

Why Light2D

• Colored per-channel transmission. Obstacles absorb and tint light per RGB channel, so shadows can be colored and materials can filter light instead of just blocking it.
• Soft ambient bounce. An optional temporal ambient-propagation pass spreads a soft fill light through open space.
• Collider-free, texture-aware occlusion. Your existing sprites, meshes, and tilemap tiles act as obstacles, without hand-placed shadow casters or colliders. Transparent tile pixels pass light.
• Scoped lighting with coverage volumes. Drop a Light2DVolume to confine lighting to caves or interiors, the classic "bright overworld, dark cave" look.
• One package, both pipelines. The same components render on the Built-in Render Pipeline and on URP's Universal and 2D Renderers.

Unity's own 2D lights cover mainstream URP lighting well. Light2D is for a different look: colored transmission, ambient bounce, and occlusion taken straight from your existing art. It is also the option that runs on the Built-in Render Pipeline. The package README compares the two in detail.

How it works

Every Light2D component registers itself when enabled and is drawn through a command buffer into low-resolution light-input textures: obstacles, direct lights, then optional ambient propagation. The result is composited over the camera image, via OnRenderImage on the Built-in pipeline and via a URP 17 RenderGraph renderer feature on URP. You never set up lighting layers, helper cameras, or culling masks. Details live in ARCHITECTURE.md.

Install

In Window > Package Management > Package Manager, choose Install package from git URL... and enter:

https://github.com/SSS135/Light2D.git?path=/Packages/com.sss13594.light2d

Point Unity at that subpath, not the repository root; the root is the development project. Pin a tag, branch, or commit by appending #<revision> after the path query. Tilemap obstacles also need the com.unity.2d.tilemap package; everything else works without it. Local-disk and embedded installs are covered in INSTALLATION.md.

First scene

1. Add a LightingSystem to your camera: GameObject > Light2D > Lighting System.
2. Add a light: GameObject > Light2D > Light Source.
3. Select existing sprites, meshes, or tilemaps and run GameObject > Light2D > Light Obstacle. The command picks the right obstacle component for the renderer.
4. URP only: install Light2DUniversalRendererFeature on the camera's renderer (the LightingSystem inspector offers Install / Repair Renderer Feature). Built-in needs no extra setup.

A freshly configured scene can look black until it contains a light source or an ambient emitter. That black screen is the lighting working.

The components

Component	Role
LightingSystem	On the camera; owns quality settings and the final composite
LightSprite	Sprite-shaped point, spot, or line light
LightObstacleSprite	Mirrors a SpriteRenderer as an occluder
LightObstacleMesh	Mirrors a MeshRenderer's mesh and texture as an occluder
LightObstacleTilemap	Texture-aware Tilemap occluder (with com.unity.2d.tilemap)
LightObstacleGenerator	Adds the right obstacle component at runtime
LightAmbientEmitter	Feeds the ambient-propagation pass
Light2DVolume	Scopes how much Light2D applies inside a region

Pipeline support

Pipeline	Status
URP 17.3+	Supported: RenderGraph renderer feature on Universal Renderer Data or 2D Renderer Data
Built-in Render Pipeline	Supported as a compatibility path via OnRenderImage
HDRP / other SRPs	Not supported; rejected with a single warning

Unity has announced Built-in's deprecation, so new projects should target URP. Current limitations (normal mapping, perspective cameras, XR, camera stacks) are listed in the package README.

Samples

Import Examples from the package's Samples list in Package Manager:

• Small Examples cycles through direct lights, sprite and mesh obstacles, ambient emitters, and normal mapping.
• Rocket is a playable lander in a colored-light cave with generated obstacle meshes (the hero clip above).
• Rocket Tilemap rebuilds the same cave from a Tilemap with the texture-aware obstacle.
• Light Volume is the "bright overworld, dark cave" coverage-volume demo (pictured above): the Light2DVolume keeps the lighting inside the cave while the overworld shows its raw art.

This repository

The repository root is the Unity 6000.5.4f1 project used to develop and test the package. Open the root in Unity, not a subfolder.

Path	Purpose
Packages/com.sss13594.light2d/	The UPM package: runtime, editor, tests, samples, docs
Assets/	Development-host scenes, sample install, and test automation
ProjectSettings/, Packages/manifest.json	Unity project configuration for the host

Documentation

• Package README
• Installation and setup
• Components, settings, and render architecture
• Frequently asked questions
• Migration and upgrade notes
• Troubleshooting
• Development and testing
• Diagnostics and benchmarking
• Changelog

License

Light2D is available under the MIT License. It began in 2017 as one of the early open-source 2D lighting assets for Unity; the original project was archived in 2018 and has been rebuilt for Unity 6 as 2.0 with a register-and-draw architecture. The package is maintained by the community and is not affiliated with Unity.