Alpha blend textures

Hello!Does anyone know where can i find a shader that can blend 2 textures based on an alpha map?So that where is white,Texture 1 is visible 100% and where it is black,Texture 2 is visible 100% and where it is gray,they are mixed.I am using unity 3.x…I found something that was using a lightmap,but it didn’t worked :frowning:
Please help me!

Anyone? :[

EDIT: Oh nevermind, i didnt read your post carefully.

I will use the Lerp function

If you have got a surfaceshader :

fixed4 texture1 = tex2D(_Texture1, IN.uv_Texture1);
fixed4 texture2 = tex2D(_Texture2, IN.uv_Texture2);
fixed alpha = tex2D(_Alpha, IN.uv_Alpha).r;
o.Albedo = lerp(texture2, texture1, alpha);

Thus, when alpha = 1 → 100% texture1
when alpha = 0 → 100% texture2
Otherwise, the lerp function blend your textures

OH,i see!
Sorry,but i am a total noob when it comes to shaders…If this would be my shader :

  Shader "Example/Rim" {
    Properties {
      _MainTex ("Texture", 2D) = "white" {}
      _BumpMap ("Bumpmap", 2D) = "bump" {}
      _RimColor ("Rim Color", Color) = (0.26,0.19,0.16,0.0)
      _RimPower ("Rim Power", Range(0.5,8.0)) = 3.0
    }
    SubShader {
      Tags { "RenderType" = "Opaque" }
      CGPROGRAM
      #pragma surface surf Lambert
      struct Input {
          float2 uv_MainTex;
          float2 uv_BumpMap;
          float3 viewDir;
      };
      sampler2D _MainTex;
      sampler2D _BumpMap;
      float4 _RimColor;
      float _RimPower;
      void surf (Input IN, inout SurfaceOutput o) {
          o.Albedo = tex2D (_MainTex, IN.uv_MainTex).rgb;
          o.Normal = UnpackNormal (tex2D (_BumpMap, IN.uv_BumpMap));
          half rim = 1.0 - saturate(dot (normalize(IN.viewDir), o.Normal));
          o.Emission = _RimColor.rgb * pow (rim, _RimPower);
      }
      ENDCG
    } 
    Fallback "Diffuse"
  }

Where do i place it?If i place your snipped in the surf function it gives a bunch of errors :frowning: Thanks!

I am using Unity 3

Oh i just found what i needed!
http://www.unifycommunity.com/wiki/index.php?title=LayerShader
Thank you for your help :smile:
This uses the same principle