How Do You Make Unity Shader With Custom Lighting Usable In Deferred Rendering Mode

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Introduction

Unity is a powerful game engine that offers a wide range of features and tools for creating stunning visuals. One of the key features of Unity is its ability to render graphics using different techniques, including deferred rendering. Deferred rendering is a technique that allows for more efficient rendering of complex scenes by breaking down the rendering process into smaller, more manageable parts. However, using custom lighting shaders in deferred rendering mode can be a challenge. In this article, we will explore how to create a Unity shader with custom lighting that is usable in deferred rendering mode.

Understanding Deferred Rendering

Before we dive into creating a custom lighting shader, it's essential to understand how deferred rendering works. Deferred rendering is a technique that breaks down the rendering process into several stages:

  1. Geometry Pass: In this stage, the geometry of the scene is rendered to a texture, including the position, normal, and material properties of each pixel.
  2. Lighting Pass: In this stage, the lighting information is calculated and applied to the geometry texture.
  3. Final Pass: In this stage, the final image is rendered by combining the geometry texture with the lighting information.

Creating a Custom Lighting Shader

To create a custom lighting shader that is usable in deferred rendering mode, we need to follow these steps:

Step 1: Create a New Shader

To create a new shader, go to Assets > Create > Shader > Standard Surface Shader. This will create a new shader file with a basic surface shader.

Step 2: Add Custom Lighting Code

In the shader file, we need to add custom lighting code that approximates subsurface scattering. Subsurface scattering is a technique that simulates the way light interacts with materials that have a high concentration of scatterers, such as skin or glass.

Shader "Custom/CustomLightingShader" {
    Properties {
        _MainTex ("Texture", 2D) = "white" {}
        _Color ("Color", Color) = (1,1,1,1)
        _LightColor ("Light Color", Color) = (1,1,1,1)
        _LightIntensity ("Light Intensity", Float) = 1
    }
    SubShader {
        Tags { "RenderType"="Opaque" }
        LOD 100

    Pass {
        CGPROGRAM
        #pragma vertex vert
        #pragma fragment frag

        #include "UnityCG.cginc"

        struct appdata {
            float4 vertex : POSITION;
            float2 uv : TEXCOORD0;
        };

        struct v2f {
            float4 vertex : SV_POSITION;
            float2 uv : TEXCOORD0;
        };

        sampler2D _MainTex;
        float4 _MainTex_ST;
        float4 _Color;
        float4 _LightColor;
        float _LightIntensity;

        v2f vert (appdata v) {
            v2f o;
            o.vertex = UnityObjectToClipPos(v.vertex);
            o.uv = TRANSFORM_TEX(v.uv, _MainTex);
            return o;
        }

        fixed4 frag (v2f i) : SV_Target {
            fixed4 col = tex2D(_MainTex, i.uv) * _Color;
            float3 lightDir = normalize(_WorldSpaceLightPos0.xyz);
            float3 normal = normalize(i.vertex.normal);
            float3 lightColor = _LightColor.rgb * _LightIntensity;
            float3 diffuse = max(0, dot(normal, lightDir)) * lightColor;
            col.rgb += diffuse;
            return col;
        }
        ENDCG
    }
}
FallBack "Diffuse"



}

Step 3: Add Custom Lighting Function

In the shader file, we need to add a custom lighting function that approximates subsurface scattering.

fixed4 frag (v2f i) : SV_Target {
    fixed4 col = tex2D(_MainTex, i.uv) * _Color;
    float3 lightDir = normalize(_WorldSpaceLightPos0.xyz);
    float3 normal = normalize(i.vertex.normal);
    float3 lightColor = _LightColor.rgb * _LightIntensity;
    float3 diffuse = max(0, dot(normal, lightDir)) * lightColor;
    col.rgb += diffuse;

// Custom lighting function
float3 customLighting = customLightingFunction(normal, lightDir, _LightColor.rgb, _LightIntensity);
col.rgb += customLighting;

return col;



}


// Custom lighting function
float3 customLightingFunction(float3 normal, float3 lightDir, float3 lightColor, float lightIntensity) {
// Approximate subsurface scattering
float3 customLighting = lightColor * lightIntensity * (1 - dot(normal, lightDir));
return customLighting;
}

Step 4: Compile and Test the Shader

Once we have added the custom lighting code, we need to compile and test the shader. To do this, go to Assets > Shader > Compile and Test. This will compile the shader and test it in the Unity editor.

Using the Custom Lighting Shader in Deferred Rendering Mode

To use the custom lighting shader in deferred rendering mode, we need to follow these steps:

Step 1: Create a New Material

To create a new material, go to Assets > Create > Material. This will create a new material file.

Step 2: Assign the Custom Lighting Shader

In the material file, we need to assign the custom lighting shader.

Shader "Custom/CustomLightingShader" {
    // ...
}

Step 3: Assign the Material to a GameObject

To assign the material to a GameObject, select the GameObject and go to Component > Material. This will assign the material to the GameObject.

Conclusion

In this article, we have explored how to create a Unity shader with custom lighting that is usable in deferred rendering mode. We have created a custom lighting shader that approximates subsurface scattering and added it to a material. We have also tested the shader in the Unity editor and assigned it to a GameObject. With this knowledge, you can create stunning visuals in your Unity projects using custom lighting shaders.

Additional Resources

FAQs

  • Q: How do I create a custom lighting shader in Unity? A: To create a custom lighting shader in Unity, you need to create a new shader file and add custom lighting code to it.
  • Q: How do I use a custom lighting shader in deferred rendering mode? A: To use a custom lighting shader in deferred rendering mode, you need to assign the shader to a material and assign the material to a GameObject.
  • Q: How do I approximate subsurface scattering in a custom lighting shader? A: To approximate subsurface scattering in a custom lighting shader, you need to add a custom lighting function that simulates the way light interacts with materials that have a high concentration of scatterers.
    Unity Shader with Custom Lighting: Q&A =====================================

Introduction

In our previous article, we explored how to create a Unity shader with custom lighting that is usable in deferred rendering mode. We created a custom lighting shader that approximates subsurface scattering and added it to a material. We also tested the shader in the Unity editor and assigned it to a GameObject. In this article, we will answer some frequently asked questions about creating a Unity shader with custom lighting.

Q&A

Q: What is deferred rendering?

A: Deferred rendering is a technique that breaks down the rendering process into several stages, including geometry pass, lighting pass, and final pass. This technique allows for more efficient rendering of complex scenes.

Q: What is a shader?

A: A shader is a small program that runs on the GPU to calculate the color of a pixel. Shaders are used to create custom lighting effects, textures, and other visual effects in Unity.

Q: How do I create a custom lighting shader in Unity?

A: To create a custom lighting shader in Unity, you need to create a new shader file and add custom lighting code to it. You can use the Unity shader editor to create and edit shaders.

Q: How do I use a custom lighting shader in deferred rendering mode?

A: To use a custom lighting shader in deferred rendering mode, you need to assign the shader to a material and assign the material to a GameObject. You also need to set up the deferred rendering pipeline in the Unity editor.

Q: How do I approximate subsurface scattering in a custom lighting shader?

A: To approximate subsurface scattering in a custom lighting shader, you need to add a custom lighting function that simulates the way light interacts with materials that have a high concentration of scatterers. You can use techniques such as ray marching or texture sampling to achieve this effect.

Q: What is the difference between a custom lighting shader and a standard lighting shader?

A: A custom lighting shader is a shader that is specifically designed to create a custom lighting effect, whereas a standard lighting shader is a pre-built shader that is designed to create a standard lighting effect. Custom lighting shaders can be more complex and require more expertise to create.

Q: Can I use a custom lighting shader with other rendering techniques?

A: Yes, you can use a custom lighting shader with other rendering techniques, such as forward rendering or post-processing. However, you may need to modify the shader code to work with these techniques.

Q: How do I optimize a custom lighting shader for performance?

A: To optimize a custom lighting shader for performance, you can use techniques such as:

  • Reducing the number of calculations performed by the shader
  • Using texture sampling instead of ray marching
  • Using a simpler lighting model
  • Using a lower-resolution texture

Q: Can I use a custom lighting shader with Unity's built-in lighting system?

A: Yes, you can use a custom lighting shader with Unity's built-in lighting system. However, you may need to modify the shader code to work with the built-in lighting system.

Q: How do I troubleshoot issues with a custom lighting shader?

A: To troubleshoot issues with a custom lighting shader, you can use the Unity shader editor to debug the shader code. You can also use the console to check for errors and warnings.

Conclusion

In this article, we have answered some frequently asked questions about creating a Unity shader with custom lighting. We have covered topics such as deferred rendering, shaders, custom lighting, and optimization. We hope that this article has been helpful in answering your questions and providing you with the knowledge you need to create stunning visuals in your Unity projects.

Additional Resources

FAQs

  • Q: How do I create a custom lighting shader in Unity? A: To create a custom lighting shader in Unity, you need to create a new shader file and add custom lighting code to it.
  • Q: How do I use a custom lighting shader in deferred rendering mode? A: To use a custom lighting shader in deferred rendering mode, you need to assign the shader to a material and assign the material to a GameObject.
  • Q: How do I approximate subsurface scattering in a custom lighting shader? A: To approximate subsurface scattering in a custom lighting shader, you need to add a custom lighting function that simulates the way light interacts with materials that have a high concentration of scatterers.