New to Shaders, question about shader for cubemap skybox transition.

Questions & Answers
1

Hello.
I’m new to shaders and trying to use the shader from (Making specific shader for texture transition effect - Questions & Answers - Unity Discussions)
for skybox cubemap transition.

I did some modification like this:

Shader "Custom/Transition" {
	Properties{
		_MainTex("Base (RGB)", CUBE) = "white" {}
	_DetailTex("Detail (RGB)", CUBE) = "white" {}
	_Guide("Guide (RGB)", CUBE) = "white" {}
	_Threshold("Threshold",Range(0,1)) = 0
	}
		SubShader{
		Tags{ "RenderType" = "Opaque" }
		LOD 200

		CGPROGRAM
#pragma surface surf Lambert
#pragma target 4.0 
	samplerCUBE _MainTex;
	samplerCUBE _DetailTex;
	samplerCUBE _Guide;
	float _Threshold;

	struct Input {
		float3 uv_MainTex;
		float3 uv_DetailTex;
		float3 uv_Guide;
	};

	void surf(Input IN, inout SurfaceOutput o) {
		half4 c = texCUBE(_MainTex, IN.uv_MainTex);
		half4 d = texCUBE(_DetailTex, IN.uv_DetailTex);
		half4 g = texCUBE(_Guide, IN.uv_Guide);
		if ((g.r + g.g + g.b)*0.33333f < _Threshold)
			o.Albedo = d.rgb;
		else
			o.Albedo = c.rgb;
		o.Alpha = c.a;
	}
	ENDCG
	}
		FallBack "Diffuse"
}

But I cannot get it to work:
Shader error in ‘Custom/Transition’: cannot implicitly convert from ‘const float2’ to ‘float3’ at line 86 (on d3d11)

Is it the right way to achieve the skybox transition effect? Thanks.

2

Shader “Custom/Transition” {
Properties{
_MainTex(“Base (RGB)”, CUBE) = “white” {}
_DetailTex(“Detail (RGB)”, CUBE) = “white” {}
_Guide(“Guide (RGB)”, CUBE) = “white” {}
_Threshold(“Threshold”,Range(0,1)) = 0
}
SubShader{
Tags{ “RenderType” = “Opaque” }
LOD 200

         CGPROGRAM
 #pragma surface surf Lambert
 #pragma target 3.0 
     samplerCUBE _MainTex;
     samplerCUBE _DetailTex;
     samplerCUBE _Guide;
     float _Threshold;
 
     struct Input {
         float2 uv_MainTex;
         float2 uv_DetailTex;
         float2 uv_Guide;
     };
 
     void surf(Input IN, inout SurfaceOutput o) {
         half4 c = texCUBE(_MainTex, IN.uv_MainTex);
         half4 d = texCUBE(_DetailTex, IN.uv_DetailTex);
         half4 g = texCUBE(_Guide, IN.uv_Guide);
         if ((g.r + g.g + g.b)*0.33333f < _Threshold)
             o.Albedo = d.rgb;
         else
             o.Albedo = c.rgb;
         o.Alpha = c.a;
     }
     ENDCG
     }
         FallBack "Diffuse"
 }