https://github.com/defold/sample-lights-and-shadows

Example of how to achieve pixel perfect shadows in a 2D view
https://github.com/defold/sample-lights-and-shadows

Last synced: 4 months ago
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Example of how to achieve pixel perfect shadows in a 2D view

• Host: GitHub
• URL: https://github.com/defold/sample-lights-and-shadows
• Owner: defold
• License: mit
• Created: 2021-07-22T21:37:45.000Z (almost 4 years ago)
• Default Branch: master
• Last Pushed: 2024-09-30T09:13:46.000Z (8 months ago)
• Last Synced: 2025-01-30T15:24:50.378Z (4 months ago)
• Language: Lua
• Homepage:
• Size: 803 KB
• Stars: 33
• Watchers: 8
• Forks: 5
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-defold - Lights and Shadows

README

        
# Lights and Shadows

Example of how to achieve pixel perfect shadows in a 2D view. The sample is based on the following sources:

* 2D Pixel Perfect Shadows LIBGDX example: https://github.com/mattdesl/lwjgl-basics/wiki/2D-Pixel-Perfect-Shadows

* Adapted to Defold with technical discussion by d954mas: https://forum.defold.com/t/problem-with-shader/3808

* Final Defold sample project by Sayuris1: https://github.com/Sayuris1/2d_light_defold

## Installation

You can use this solution in your own project by adding this this project as a Defold library dependency. Open your game.project file and in the dependencies field under project add:

https://github.com/defold/sample-lights-and-shadows/archive/master.zip

## Usage

The main components of this light and shadow casting example are:

* `lights/lightsource.script` - Attach this script to any game object that should act as a lightsource. Modify the exposed script properties to control the light properties:

   * `radius` [number] - Radius of the lightsource in pixels

   * `color` [vector4] - Color of the lightsource (RGBA)

   * `arc_angle` [number] - Arc angle of the lightsource. Can be used to generate a cone of light up to an arc angle of 180 degrees. Anything above 180 degrees will result in a full circle.

   * `static` [boolean] - Use this for static lights that do not move or rotate to skip updates of light position and rotation each frame.

   * `falloff` [number] - This controls the light intensity. With a falloff of 1.0 the light intensity gradually decreases until there is no light right at the edge. With a falloff of 2 the light intensity decreases twice as fast.

   * `enabled` [boolean] - Set to false to disable the light.

* `lights/render/light_quad.go` - A game object with a basic model quad, used as a render target when drawing lights and shadows.

* `lights/render/lights.render` and `lights/render/lights.render_script` - The render file and render script used when drawing lights and shadows (and also all of the standard Defold components such as sprites, particles, tilemaps etc)

* `lights/materials/light_occluder_*.material` - Materials to use for sprite, tilemaps and other components that should occlude light and cast shadows.

### Step 1 - Render script

Open **game.project** and scroll down to `Bootstrap` and change Render file to `lights/render/lights.render`. This render script works like the default render script with the addition of also drawing lights and shadows.

![](/docs/add_render_file_to_bootstrap.png)

### Step 2 - Add light quad

Add the `lights/render/light_quad.go` to a collection where lights and shadows should be calculated.

![](/docs/add_light_quad.png)

### Step 3 - Add lightsources

Attach the `lights/lightsource.script` to any game object that should act as a lightsource.

![](/docs/add_lightsource.png)

Configure the lightsource properties to your liking.

![](/docs/configure_lightsource.png)

### Step 4 - Add light occluders

Change the material for any component that should cast shadows when lit by a lightsource. Select a material from `lights/materials/` matching the component type casting shadows.

![](/docs/configure_light_occluder.png)

## Example

There is an example included in this repository. It sets up a few lightsources and occluders and lets you move around the scene.

![](/docs/example.png)