Oct
12
2014

2D Visibility / Shadow

An article by mgear

2d_visibility_shadow_casting_unity_1

Started converting this 2D visibility/light script ( http://ncase.me/sight-and-light/ ) to unity, finally some progress!
btw. lines are drawn using GLDebug from : http://www.unity3d-france.com/unity/phpBB3/viewtopic.php?f=24&t=5409

Unity forum thread: http://forum.unity3d.com/threads/2d-visibility-shadow-free.275698/

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TODO:
~~– Quad segments are currently crossed..~~
~~– Fix mesh generation~~ *Temporary fix: insert extra boxes outside the view..
– Source cleaning up
~~– Publish to github~~
– Optimize
– Some documentation
– Try raster version (bresenham + floodfill)
– Support for moving objects
– Sprite support (but unity indie has quad sprite mesh, no tight mesh generation..needs extra script to generate helper points for sprite image edges..?)
– Better system for finding edge segments
– …

Stats:
– 20 obstacles (~80 vertices) : ~45-50ms per frame (in editor, with slow’ish pc)

Webplayer:
http://unitycoder.com/upload/demos/2DVisibility/v1/ (v1, still broken)
http://unitycoder.com/upload/demos/2DVisibility/v2/ (v2, almost done)

Source:
https://github.com/unitycoder/2DShadow (Please help improving the code!)

Previous attempt:
Shadow casting 2D : http://unitycoder.com/blog/2014/02/10/shadow-casting-2d/ (using pseudo angles, unfinished

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Image#2: Few problems fixed, mesh still broken..somehow cannot make the light vertices go in to “correct” world space(?)

2d_visibility_shadow_casting_unity_2

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Image#3: Mesh fixed, but still starts “stretching” when mouse moves away from center..

2d_visibility_shadow_casting_unity_3

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Image#4: Good enough..(added hidden boxes outside the view, to avoid broken mesh *hidden box idea from denamond)

2d_visibility_shadow_casting_unity_4

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Image#5: Current profiler view, gets quite slow with many objects..need to start optimizing

(click image to view)

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Image#6: Testing visibility with Martt’s dual camera depth mask system (see the 2nd sphere is partly hidden)

2d_visibility_shadow_casting_unity_camera_mask_5

Tags: 2d, light, line of sight, LOS, shadow, view, visibility

About the Author:

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31 Comments + Add Comment

Tom Spring 22/10/2014 at 05:37

Hey, did you ever get around to releasing the code to this, I would be really interested?

Reply
- mgear 22/10/2014 at 09:03
  
  yeah, very soon (inital versio is ready for github, just didnt have the time yet : )
  
  Reply
  - Tom Spring 22/10/2014 at 22:27
    
    Cheers mate, I appreciate it!
    
    Reply
    - mgear 23/10/2014 at 17:31
      
      Its alive: https://github.com/unitycoder/2DShadow
      
      Reply
      - CFREE 23/10/2014 at 18:07
        
        Hi, the source files in GitHub looks broken (the total size is 37 kb).
        
        Man, thanks for your great contribution for indies developers.
      - mgear 23/10/2014 at 18:13
        
        Github zip looks ok, its quite small since there are no images, not much code either etc. (that image#6 demo is not included, as it was just quickly hacked together…needs work/cleaning up)
  - Tom Spring 23/10/2014 at 18:38
    
    You’re a genius man! Everything is working with no errors, just wanted to know where the scripts go and how I make the scene. Thanks again, so much!
    
    Reply
mgear 06/11/2014 at 15:52

2D Dynamic Lights and Shadows (free, works with sprites)
https://www.assetstore.unity3d.com/#!/content/24083?aid=1101lGti

Reply
martin 04/12/2014 at 19:17

Hi mgear, i’ve try to get effect like –> Image#6: Testing visibility with Martt’s dual camera depth mask system — > but i can’t get it.
can you send me a little help ?

Reply
- mgear 04/12/2014 at 20:25
  
  I downloaded his demo package,
  http://forum.unity3d.com/threads/skynox.124019/#post-1007954
  And removed all the extras, expect the dual camera system.
  
  Reply
  - martin 05/12/2014 at 14:01
    
    thanks man, but I still can not get it,. Can you post the project file and see what I am doing wrong?
    
    Reply
mgear 06/02/2015 at 11:21

This one has nice features!
2D Light of Sight:
https://github.com/f15gdsy/2D-Light-of-Sight-Unity

Reply
mgear 19/03/2015 at 11:05

2D per pixel shadow maps:
https://github.com/brianasu/2d-pixelshadows

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mgear 06/05/2015 at 11:36

VLS2D is a 2D light creation system:
https://github.com/reveriejake/VLS2D

Reply
mgear 29/05/2015 at 12:34

vishull2d (Computes the visible region from a point for a given environment represented by a collection of line segments) *javascript (not unity):
https://github.com/mikolalysenko/vishull2d

Reply
ONeil 06/07/2015 at 17:55

Damn man, i love you. Amazing work!

Reply
mgear 26/12/2015 at 18:14

Field-of-View
https://github.com/SebLague/Field-of-View

Reply
mgear 05/04/2016 at 14:09

Vector lighting explained
https://www.facebook.com/notes/monaco/vector-lighting-explained/395139091995/

Reply
mgear 15/06/2017 at 17:04

A simple 2d/3d visibility effect in Unity
https://github.com/OskarSigvardsson/2d-3d-visibility

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mgear 21/02/2018 at 19:34

using 3D objects and light to cast 2D shadows:
http://piranhacms.org/blog/fast-beautiful-2d-lighting-in-unity

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mgear 27/02/2018 at 10:57

Fast 2D shadows in Unity using 1D shadow mapping
https://www.gamasutra.com/blogs/RobWare/20180226/313491/Fast_2D_shadows_in_Unity_using_1D_shadow_mapping.php/

Reply
mgear 26/07/2019 at 02:02

Realtime 2D Raytracing in Unity using Signed Distance Fields
https://github.com/Robert-K/light2D

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mgear 18/09/2019 at 17:16

2D SDF Shadows
https://www.ronja-tutorials.com/2018/12/01/2d-shadows.html

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mgear 21/10/2019 at 14:32

VisibilityPolygonCSharp
https://github.com/xaviergonz/visibility-polygon-csharp

Reply
mgear 20/04/2020 at 18:12

2D lighting system using commandbuffer
https://github.com/SardineFish/Unity2DLighting

Reply
mgear 15/11/2020 at 16:56

GPU Line of Sight / Field of View visualization for Unity
https://github.com/EntroPi-Games/GPU-Line-of-Sight

Reply
mgear 18/01/2021 at 10:46

tilemap shadow casting
https://github.com/BrianCraig/Tilemap-Shadow-Caster

Reply
mgear 08/03/2021 at 09:48

Field of view visualisations
https://github.com/SebLague/Field-of-View

Reply
mgear 10/04/2022 at 18:28

visibility using sprite mask
https://forum.unity.com/threads/how-can-i-show-only-the-part-of-a-sprite-thats-behind-a-mask.1265504/

Reply
mgear 21/04/2022 at 14:23

Script for generating ShadowCaster2Ds for Tilemaps
https://forum.unity.com/threads/script-for-generating-shadowcaster2ds-for-tilemaps.906767/

Reply
mgear 02/10/2023 at 21:09

cast rays on the edges of nearby objects and then filling the space between the rays by generating a mesh
https://github.com/aniketrajnish/optimized-2d-lighting-unity

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