Overlaying a texture over another one but with 2 materials

So I got a map that used UV2 for lightmaps. I tried doing something like this http://i.imgur.com/xNPKM9l.png where one of the shader has something like:

"o.Albedo = c.rgb;"

and the other shader something like:

"o.Albedo *= c.rgb;"

But when accessing o.Albedo it appears to always be a black color and not the previous set one..

I am pretty new to shaders if u didn't notice, sarcasm

 

Code (CSharp):

1.  
2.  
3. Shader "Custom/Diffuse Layer"
4. {
5.     Properties
6.     {
7.         _Color ("Color", color) = (1.0, 1.0, 1.0, 1.0)
8.         _Tex1("Tex1", 2D) = "white" {}
9.         _Tex2("Tex2", 2D) = "white" {}
10.         _Mix ("Mix", range(0.0, 1.0)) = 0.5
11.     }
12.  
13.     SubShader
14.     {
15.         Tags { "RenderType"="Opaque" "LightMode" = "ForwardBase" }
16.  
17.         Pass
18.         {
19.             CGPROGRAM
20.  
21.             #pragma vertex vert
22.             #pragma fragment frag
23.  
24.             #include "UnityCG.cginc"
25.  
26.             uniform float4 _Color;
27.             uniform sampler2D _Tex1;
28.             uniform sampler2D _Tex2;
29.             uniform float4 _LightColor0;
30.             uniform float _Mix;
31.  
32.             struct vertIn
33.             {
34.                 float4 pos : POSITION;
35.                 float4 texCoord : TEXCOORD0;
36.                 float4 col : COLOR;
37.                 float3 norm : NORMAL;
38.             };
39.  
40.             struct vertOut
41.             {
42.               float4 pos : SV_POSITION;
43.               float4 texCoord : TEXCOORD0;
44.               float4 col : COLOR;
45.             };
46.  
47.             vertOut vert(vertIn input)
48.             {
49.               vertOut output;
50.  
51.               output.pos = mul(UNITY_MATRIX_MVP, input.pos);
52.  
53.               output.texCoord = input.texCoord;
54.  
55.               float4 norm = float4(input.norm, 0.0);
56.               float3 surfaceNormal = normalize(mul(norm, _World2Object));
57.               float3 lightDirection = normalize(_WorldSpaceLightPos0);
58.               float3 NdotL = max(0.0, dot(surfaceNormal, lightDirection));
59.               float3 dotProduct = NdotL * _LightColor0 * _Color;
60.               float3 ambientLight = UNITY_LIGHTMODEL_AMBIENT * _Color;
61.               float4 col = float4(dotProduct + ambientLight, 1.0);
62.               output.col = col;
63.  
64.               return output;
65.             }
66.  
67.             struct fragOutput
68.             {
69.                 float4 col : COLOR;
70.             };
71.  
72.             fragOutput frag(vertOut input)
73.             {
74.                 fragOutput output;
75.  
76.                 float4 col1 = tex2D(_Tex1, input.texCoord);
77.                 float4 col2 = tex2D(_Tex2, input.texCoord);
78.  
79.                 output.col = input.col;
80.  
81.                 output.col *= lerp(col1, col2, _Mix);
82.  
83.                 return output;
84.             }
85.             ENDCG
86.         }
87.     }
88. }

 

Well that wont really work since both materials are supposed to work with different submeshes

 

Then use one submesh and an alpha texture?

 

In your overlay materials shader, use a multiplicative blend mode.
Read the shaderlab refference in the manual on how to do so.