# MoonlightVRC

## Disclaimer

This project seems similar, but the person seems to have more of a clue about what they are doing: https://github.com/z3y/ClusteredBIRP

## Idea

When creating a World for VRChat that reveals items around the player as they walk up to them, I stumbled across the problem that Quest doesn't handle real-time lights well. As a result, I may have ended up spending tens of hours coding my own light system.

What this includes:
- Point/spotlights editable at runtime.
- A couple of premade shaders (standard, particle).
- Premade code handling lights, normals and a Lambertian diffuse.
- Shadow caster planes

Work in progress:
- Water shader
- Documentation
- More performance testing/improvements

  
Planned:
- Support for additive baked light maps and ambient lighting in the standard shader.
  
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## Performance

Early testing showed the Quest 3 dropping to around 30 FPS when having 100 spotlights active in a scene at once. This test was conducted with 5 material targets. Since then the shader has grown in size significantly there has been optimisation

On PC, I haven't encountered any frame drops in the editor at all, even with 400 concurrent lights.

## Quick start

1. Clone the code into your project.

2. Add the `LightUpdater` component to a GameObject in your scene:
   - Tweak strength/intensity of the local and remote player if you want them to have an attached light.
   - Configure the `PlayerShadowMapIndex` if you want players to interact with shadows.

3. For lights, attach `LightdataStorage` to a Transform and configure:
   - `range`, `lightType`, `color`, `intensity`, `spotAngleDeg`, and `shadowMapIndex`.
  
4. On your light's `LightdataStorage` component, assign your scene's `LightUpdater` to the `Light Updater` field. This allows lights to be added or removed dynamically at runtime.

5. Use one of the premade shaders on your material. Or, if you feel like it, use the provided .hlsl/.cginc in your own shader. You just need to copy everything surrounded by Moonlight comments, and apply it at the end of your shader.

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## Editor preview

- While not in play mode, the editor helper `LightUpdaterPreview` (EditorPreview/Editor/LightUpdaterPreview.cs) and `ShadowcasterUpdaterPreview` (EditorPreview/Editor/ShadowcasterUpdaterPreview.cs) write the same property blocks to assigned Renderers so you can preview lighting effects in the Scene view. Those update 10 times a second.
- The editor partial helper for building preview arrays is in `EditorPreview/LightUpdater.Editor.cs`.

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## Tips

- Match `maxLights` in the component with the `#define MAX_LIGHTS` in your shaders (default is 80 — see Performance).
  
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## Contributing

If you want to help with development, please contact me on Discord (@demuenu) so we can coordinate our efforts.
If your somebody with a education in Computer graphics, I would be even more thankful for your help. As right now, it's just me with ~1.5 years of messing around in Shaderlab and ChatGPT as my advisor. So I'm sure that there are serious flaws in the codebase :-)