How to disable fog on Particle System shader in Unity

Particle System effect fog resistant in Solomon Snow — First Contact game.

As we can see here, we use the fog to nicely blend the background of the entire level. Emitting stars under the “You have reached level” are a special effect of Particle System with a custom shader based on Mobile/Particles/Additive.

The solution is very simple. You can make your own shader based on the original with a little change. Here are the steps:

• Download always the newest shaders from the unity site:
  http://unity3d.com/download_unity/builtin_shaders.zip
• Unpack and find your shader, in our case it was builtin_shaders/DefaultResourcesExtra/Mobile/Mobile-Particle-Add.shader

// Unity built-in shader source. Copyright (c) 2016 Unity Technologies. MIT license (see license.txt)
// Simplified Additive Particle shader. Differences from regular Additive Particle one:
// - no Tint color
// - no Smooth particle support
// - no AlphaTest
// - no ColorMask
Shader "Mobile/Particles/Additive" {
Properties {
    _MainTex ("Particle Texture", 2D) = "white" {}
}
Category {
    Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent" "PreviewType"="Plane" }
    Blend SrcAlpha One
    Cull Off Lighting Off ZWrite Off Fog { Color (0,0,0,0) }
BindChannels {
        Bind "Color", color
        Bind "Vertex", vertex
        Bind "TexCoord", texcoord
    }
SubShader {
        Pass {
            SetTexture [_MainTex] {
                combine texture * primary
            }
        }
    }
}
}

• Duplicate this shader, change file name for-example to AdditiveDisabledFog.shader and inside code change to Shader “Mobile/Particles/Additive”. Save it!
• Now open duplicated shader file, try to find Fog { Color (0,0,0,0 } and change it to Fog { Mode Off } like this:

// Unity built-in shader source. Copyright (c) 2016 Unity Technologies. MIT license (see license.txt)
 
// Simplified Additive Particle shader. Differences from regular Additive Particle one:
// - no Tint color
// - no Smooth particle support
// - no AlphaTest
// - no ColorMask
 
Shader "Mobile/Particles/AdditiveDisabledFog" {
    Properties{
        _MainTex("Particle Texture", 2D) = "white" {}
    }
 
        Category{
            Tags { "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent" "PreviewType" = "Plane" }
            Blend SrcAlpha One
            Cull Off Lighting Off ZWrite Off Fog { Mode Off }
 
            BindChannels {
                Bind "Color", color
                Bind "Vertex", vertex
                Bind "TexCoord", texcoord
            }
 
            SubShader {
                Pass {
                    SetTexture[_MainTex] {
                        combine texture * primary
                    }
                }
            }
    }
}

• Put this shader inside your project, and change on Particle System effect to your customized shader.

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