Blending materials with mask

Hey guys.

I have a scene which I want to bring in Unity from 3D MAX but I have a problem here.
I have custom polygonal terrain, and I want to use it in Unity as well.

If you look in attached picture you will see that different ground materials are blending via the gray-scale mask map I painted.

Is here in Unity something like that, which I can use with imported polygonal surfaces?

Or how it difficult to make shader like this?

T hanks!

 

OK.. But at least blend textures with masks help is is possible to make?

 

You may pack masks in texture like:
http://gyazo.com/3b5d94dddd788dd3964cb6396a614e4f
http://gyazo.com/56396127bca517d1e9195e071023a9dd
And use a shader that blends textures by mask values.
It's slightly modified first pass of standard terrain shader.

Code (csharp):

1.  
2. Shader "Custom/DiffuseSplatMap"
3. {
4.     Properties
5.     {
6.         _Control ("Control (RGBA)", 2D) = "red" {}
7.         _Splat3 ("Layer 3 (A)", 2D) = "white" {}
8.         _Splat2 ("Layer 2 (B)", 2D) = "white" {}
9.         _Splat1 ("Layer 1 (G)", 2D) = "white" {}
10.         _Splat0 ("Layer 0 (R)", 2D) = "white" {}
11.             // used in fallback on old cards & base map
12.         _MainTex ("BaseMap (RGB)", 2D) = "white" {}
13.         _Color ("Main Color", Color) = (1,1,1,1)
14.     }
15.        
16.     SubShader
17.     {
18.             Tags
19.             {
20.                 "Queue" = "Geometry-100"
21.                 "RenderType" = "Opaque"
22.             }
23.         CGPROGRAM
24.         #pragma surface surf Lambert
25.         struct Input
26.         {
27.             float2 uv_Control : TEXCOORD0;
28.             float2 uv_Splat0 : TEXCOORD1;
29.         };
30.  
31.         sampler2D _Control;
32.         sampler2D _Splat0,_Splat1,_Splat2,_Splat3;
33.  
34.         void surf (Input IN, inout SurfaceOutput o)
35.         {
36.             fixed4 splat_control = tex2D (_Control, IN.uv_Control);
37.             fixed3 col;
38.             col  = splat_control.r * tex2D (_Splat0, IN.uv_Splat0).rgb;
39.             col += splat_control.g * tex2D (_Splat1, IN.uv_Splat0).rgb;
40.             col += splat_control.b * tex2D (_Splat2, IN.uv_Splat0).rgb;
41.             col += splat_control.a * tex2D (_Splat3, IN.uv_Splat0).rgb;
42.             o.Albedo = col;
43.             o.Alpha = 0.0;
44.         }
45.         ENDCG  
46.     }
47.  
48.     // Fallback to Diffuse
49.     Fallback "Diffuse"
50. }
51.  
52.  

Result:
http://gyazo.com/a5e4f5bfd466961014559452d3d5922c
Try google for:"splat mapping".

 

Thank you much mouurusai!

One more question: I am going to sell my asset in Unity and my own stories.
Can I include your shader code into it?

 

Yes of course, but I don't think that is production ready.

 

Thank you mouurusai.
I hope it will be enough for demo-scene if there is nothing again I can find.