# One sided plane light problem (black side) **URL:** \ **Category:** Rendering\ **Tags:** Shadows, black, unreal-engine, Lighting, question\ **Created:** [November 23, 2015, 11:58am UTC](https://forums.unrealengine.com/t/one-sided-plane-light-problem-black-side/339418 "2015-11-23T11:58:02Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Thunderon](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Thunderon](https://forums.unrealengine.com/u/Thunderon)\ **Post date:** [November 23, 2015, 11:58am UTC](https://forums.unrealengine.com/t/one-sided-plane-light-problem-black-side/339418/1 "2015-11-23T11:58:02Z")
Hi guys, I’ve got a problem with one sided plane that I want to light. On one side it has good lighting [http://i.imgur.com/8S38WCH.jpg](http://i.imgur.com/8S38WCH.jpg) But on the other side it’s black. [http://i.imgur.com/kyhlOoA.jpg](http://i.imgur.com/kyhlOoA.jpg) So is there any way to light up both sides? I’ve tried two sided material, double sided geometry, two sided lighting, cast shadow as two sided, subsurface shading model with subsurface color on it and none of it works. What should I do? ---
**Author:** ![Luos](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/luos/32/918700_2.png) [@Luos](https://forums.unrealengine.com/u/Luos)\ **Post date:** [November 23, 2015, 1:19pm UTC](https://forums.unrealengine.com/t/one-sided-plane-light-problem-black-side/339418/2 "2015-11-23T13:19:07Z")
hmm… Have you tried two sided foliage instead of subsurface? it _might_ work. ---
**Author:** ![Thunderon](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Thunderon](https://forums.unrealengine.com/u/Thunderon)\ **Post date:** [November 23, 2015, 2:27pm UTC](https://forums.unrealengine.com/t/one-sided-plane-light-problem-black-side/339418/3 "2015-11-23T14:27:27Z")
Actually it did work, thank you very much 🙂 So the problem now is that the name of shading is quite misleading since I wasn’t even aware that this might do the trick, but lessons learned so cool. ---
**Author:** ![Luos](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/luos/32/918700_2.png) [@Luos](https://forums.unrealengine.com/u/Luos)\ **Post date:** [November 23, 2015, 2:30pm UTC](https://forums.unrealengine.com/t/one-sided-plane-light-problem-black-side/339418/4 "2015-11-23T14:30:38Z")
Hmm, it was just an educated guess. Didnt expect it to work, but glad to know it did 🙂 ---
**Author:** ![Thunderon](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Thunderon](https://forums.unrealengine.com/u/Thunderon)\ **Post date:** [November 23, 2015, 3:00pm UTC](https://forums.unrealengine.com/t/one-sided-plane-light-problem-black-side/339418/5 "2015-11-23T15:00:24Z")
Yup, its a happy EOT 🙂 And for the record beautifuly lighted curtain [http://i.imgur.com/8Tk2XDz.jpg](http://i.imgur.com/8Tk2XDz.jpg) ---
**Author:** ![Sergei.k](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Sergei.k](https://forums.unrealengine.com/u/Sergei.k)\ **Post date:** [January 12, 2016, 7:33pm UTC](https://forums.unrealengine.com/t/one-sided-plane-light-problem-black-side/339418/6 "2016-01-12T19:33:31Z")
But still… If you have totally different lighting from 2 sides (let’s say it’s a thin wall) - then how it should work? As two sided foliage is more translucent material than 2 sided. ---
**Author:** ![Luos](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/luos/32/918700_2.png) [@Luos](https://forums.unrealengine.com/u/Luos)\ **Post date:** [January 12, 2016, 11:18pm UTC](https://forums.unrealengine.com/t/one-sided-plane-light-problem-black-side/339418/7 "2016-01-12T23:18:33Z")
You wouldn’t make a wall out of a flat plane, you’d make it a solid two sided mesh. Thats just not how it works. ---
**Author:** ![michaelheronsgate](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@michaelheronsgate](https://forums.unrealengine.com/u/michaelheronsgate)\ **Post date:** [April 29, 2017, 4:30am UTC](https://forums.unrealengine.com/t/one-sided-plane-light-problem-black-side/339418/8 "2017-04-29T04:30:57Z")
Not necessarily, it really depends on the project. Suppose you _do_ want to have a thin double sided object light normally? ---
**Author:** ![sevenman0](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@sevenman0](https://forums.unrealengine.com/u/sevenman0)\ **Post date:** [September 29, 2020, 12:56pm UTC](https://forums.unrealengine.com/t/one-sided-plane-light-problem-black-side/339418/9 "2020-09-29T12:56:04Z")
The answer is choosen is not a good answer i beleive. make you material shading model Subsarface and add a very black color to the subsurface color. This way you can achive super result as you expected… ---
**Author:** ![VR\_Center](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@VR\_Center](https://forums.unrealengine.com/u/VR_Center)\ **Post date:** [January 26, 2021, 9:24pm UTC](https://forums.unrealengine.com/t/one-sided-plane-light-problem-black-side/339418/10 "2021-01-26T21:24:55Z")
In reality, there is no such thing as 2D. In fact, if you want to make a game that supports ray tracing, dynamic, or static lighting, every 3D object you have should have an inside and an outside and be able to “hold water” inside it without leaking. The idea is that you never want light or a raycast of any kind to hit the back of a face. The normal of every face on a model should be pointing out, never in.