Help with adding a normalmap to a shader

Hello,

I am working with several artists on a game and we need to use real time texture blending in our game. We have been working with the following shader to achieve that affect:

Shader "Custom/ThreeTextures" {
	Properties {
            _Color ("Color Tint (A = Opacity)", Color) = (1,1,1,1)
            _Blend1 ("Blend", Range (0, 1)) = 0.0
            _Blend2 ("Blend", Range (0, 1)) = 0.0
            _MainTex1 ("Base (RGB)", 2D) = "red"
            _MainTex2 ("Base (RGB)", 2D) = "blue"
            _MainTex3 ("Base (RGB)", 2D) = "green"
        }
 
SubShader {
            Pass {
                Lighting On  
                ZWrite On
 
                Material {
                    Diffuse [_Color]
                    Ambient [_Color]
                }
 
                SetTexture [_MainTex1]{}
 
                SetTexture [_MainTex2] {
                    constantColor (0, 0, 0, [_Blend1])
                    combine texture lerp (constant) previous 
                    }
 
 
 
 
                SetTexture [_MainTex3] {
                    constantColor (0, 0, 0, [_Blend2])
                    combine texture lerp (constant) previous
                    }
 
 
            }
        } 
	FallBack "Diffuse"
}

Each of the three textures used on each object would use the same normalmap, but I’ve been working on this for weeks and I can’t understand how to combine the above shader with a surface shader. My artists are mad at me because their textures don’t look quite right without the normalmaps. Any help would be greatly appreciated, even if you can just point me in the general right direction of accomplishing this. Thanks!

I continued poking around and researching and was able to come up with a solution that worked for me, I will post it below.

`Shader “Custom/BumpedFade” {
Properties {
_Color (“Color Tint (A = Opacity)”, Color) = (1,1,1,1)
_Blend1 (“Blend”, Range (0, 1)) = 0.0
_Blend2 (“Blend”, Range (0, 1)) = 0.0
_MainTex1 (“Base (RGB)”, 2D) = “red”
_MainTex2 (“Base (RGB)”, 2D) = “blue”
_MainTex3 (“Base (RGB)”, 2D) = “green”
_BumpMap (“Normalmap”, 2D) = “bump” {}
}

SubShader {
	Tags { "RenderType"="Opaque" }
	LOD 300
	CGPROGRAM
	#pragma surface surf Lambert

	sampler2D _MainTex1;
	sampler2D _MainTex2;
	sampler2D _MainTex3;
	sampler2D _BumpMap;
	float _Blend1;
	float _Blend2;
	fixed4 _Color;

	struct Input {
		float2 uv_MainTex1;
		float2 uv_BumpMap;
	};

	void surf (Input IN, inout SurfaceOutput o) {
		//fixed4 c = tex2D(_MainTex1, IN.uv_MainTex1) * _Color;
		fixed4 main = tex2D(_MainTex1, IN.uv_MainTex1);
			fixed4 main2 = tex2D(_MainTex2, IN.uv_MainTex1);
			fixed4 main3 = tex2D(_MainTex3, IN.uv_MainTex1);
			fixed4 m1 = lerp(main, main2, _Blend1);
			fixed4 m2 = lerp(main2, main3, _Blend2);
			fixed4 m3 = lerp(m1, m2, _Blend2);
		o.Albedo = m3.rgb;
		o.Alpha = m3.a;
		o.Normal = UnpackNormal(tex2D(_BumpMap, IN.uv_BumpMap));
	}
    ENDCG         
}


FallBack "Diffuse"

}
`