PixelPerfectShadowCaster2D-Unity

Pixel Perfect Shadow Caster (2D) for Unity using Contour Tracing!

Comparison between the following shape providers:

• SpriteRenderer that uses Sprite.vertices
• PolygonCollider2D that uses Sprite.GetPhysicsShape
• PixelPerfectShadowCaster2D that uses contour tracing (ours)

How To Use

• Download either:
  • PixelPerfectShadowCaster2D.cs & PixelPerfectSpritePathCalculator.cs
  • latest .unitypackage from Releases
• Import scripts into project
• Attach this script to a shadow-casting sprite
• Make sure the sprite has Read/Write Enabled in texture import settings
• Change the Casting Source of ShadowCaster2D to Polygon Collider 2D
• Change the Trim Edges of ShadowCaster2D to 0
• Set the Alpha Threshold to the desired value, any pixel with alpha < threshold will be trimmed
• Remove the script from the sprite after using it

Note

Using the PolygonCollider2D as a mediator to set the path of the ShadowCaster2D instead of directly applying it as Unity recommends leaving the code within UnityEngine.Rendering.Universal untouched!

px_perf_shadow_cast_2d_how_to.mp4

Contributing

Contributions to the project are welcome.

License

MIT

Acknowledgement

Thankful to RandomiaGaming for Contour Tracing Algorithm.