Depth-based Shader for dungeon lighting

Hello,

I want to achive this kind of lighting effect for a retro dungeon crawler:



I allready searched half of the internet to get the idea, but i dont even know that this kind of effect or lighting or shading is called.

I dont want a smooth lighting like its built-in in unity. Instead i want a pixelated lighting for my 3D dungeon so it better fit with the pixel/retro look of the textures and 2D sprites. In addition to that i want this kind of depth/fog effect like in the picture.

Can someone tell me how to achive this kind of lighting/shading? anything would help. Thank you really much!

kind regards,

Jiraboas

 

Hi,

a simple solution would be to use a custom lighting function in your surface shader, that is used to create the banding effect.

It can be done in various ways, here are two examples:

1. As shown in the attached example project, just throwing away precision.
2. Using an additional texture that describes the falloff. A smooth gradient from white to black would be a linear falloff, but if you only use 10 colors for that white/black gradient, you would have banding. This is a nice and flexible solution, because it gives the artist very precise control of this effect. You use the NdL (Normal dot Lightdirection) to sample this texture to shade a pixel. You can take a look at the Toon Ramp example which is using this technique for a different but similar manner.

Fog can be done using simply Unity's fog system, found under Edit > Render Settings.

Here is a video of the example I just threw together for you. It is just something to look at and maybe it proves useful, I don't know. It's definitely not a fully-fledged retro dungeon solution. The download link can be found at the bottom of my post.

The idea is that the character controller moves a point light around, so you get that lighting around the player. The corridor fades to black using fog.

Here is the shader code that implements a custom lighting function to implement the banding effect. It can be found in the example project at "Assets/NewShader.shader".

Code (csharp):

1. // this is the "Diffuse" shader example from
2. // http://docs.unity3d.com/Manual/SL-SurfaceShaderLightingExamples.html
3. // what has been added is the "Band" function which will cause the banding of the light
4. Shader "Example/Diffuse Texture" {
5. Properties {
6.   _MainTex ("Texture", 2D) = "white" {}
7.   _Banding ("Banding", float) = 11
8. }
9. SubShader {
10. Tags { "RenderType" = "Opaque" }
11. CGPROGRAM
12.    #pragma surface surf SimpleLambert
13.    float _Banding;
14.  
15.    float Band(float value)
16.    {
17.      return ((int)(value*(int)_Banding) / _Banding);
18.    }
19.  
20.    half4 LightingSimpleLambert (SurfaceOutput s, half3 lightDir, half atten) {
21.     half NdotL = dot (s.Normal, lightDir);
22.     half4 c;
23.     c.rgb = s.Albedo * _LightColor0.rgb * Band(NdotL * atten * 2);
24.     c.a = s.Alpha;
25.     return c;
26.    }
27.  
28.    struct Input {
29.     float2 uv_MainTex;
30.    };
31.  
32.    sampler2D _MainTex;
33.  
34.    void surf (Input IN, inout SurfaceOutput o) {
35.     o.Albedo = tex2D (_MainTex, IN.uv_MainTex).rgb;
36.    }
37. ENDCG
38. }
39. Fallback "Diffuse"
40. }

Example project of video above (created in Unity 4.6 beta):
http://www.console-dev.de/bin/UnityRetroDungeonShading.zip

I hope it helps you get started.

 

thank you very much for your amazing effort!

This is what i needed to start with. Thanks

kind regards,

Jira

 

Hi, is it possible to do such an effect with a shadergraph?
best regards

 

Yes, just use a depth node and multiply the result. Feel free to ask in the shadergraph section. As the thread contains outdated information for a different pipeline Unity is deprecating, I'll lock this thread.