Rotating a single texture and not the whole UV

Hello guys.

I've got two texture samples. One is the main texture, and the other is used for color mask (using RGB values).

I managed to rotate the texture using a range value (0 to 360). But I want that only to affect the first (main) texture and not the second one. Obviously because it would mess up the parts I need to mask on my mesh.

How would I achieve that?

Here is the code:

Code (CSharp):

1. Shader "Dummy/Test" {
2.  
3.     Properties {
4.         _FirstTex ("Texture 1", 2D) = "white" {}
5.         _ColorMask ("ColorMask", 2D) = "white" {}
6.         _Rotation ("Rotation", Range(0.0, 360.0)) = 0.0
7.     }
8.     SubShader {
9.         Tags { "RenderType"="Opaque" }
10.         Blend One One
11.         LOD 200
12.      
13.         CGPROGRAM
14.         #pragma surface surf Lambert
15.          #pragma vertex vert
16.          sampler2D _FirstTex;
17.          sampler2D _ColorMask;
18.  
19.         struct Input {
20.             float2 uv_FirstTex;
21.             float2 uv_ColorMask;
22.         };
23.         float _Rotation;
24.      
25.         void vert (inout appdata_full v) {
26.             float rot = _Rotation / (57.2957795131);
27.             float sinX = sin (rot);
28.             float cosX = cos (rot);
29.             float sinY = sin (rot);
30.             float2x2 rotationMatrix = float2x2( cosX, -sinX, sinY, cosX);
31.             v.texcoord.xy = mul ( v.texcoord.xy, rotationMatrix );
32.         }
33.         void surf (Input IN, inout SurfaceOutput o) {
34.             half4 c = tex2D (_FirstTex, IN.uv_FirstTex);
35.             half4 c2 = tex2D (_ColorMask, IN.uv_ColorMask);
36.          
37.             o.Albedo = (c.rgb * c2.r); //Dummy code here
38.             o.Alpha = c.a;
39.         }
40.      
41.         ENDCG
42.     }
43.     FallBack "Diffuse"
44. }
45.  

Thanks for any response.

EDIT:
Nevermind, just realized I can use multiple CGPROGRAM in a shader. Excuse me, ahem.

 

Why would you use multiple CGPROGRAM for this? You just need to send two sets of UVs to the surface shader, one modified by your rotation and one not.

Code (CSharp):

1. Shader "Dummy/Test" {
2.     Properties {
3.         _FirstTex ("Texture 1", 2D) = "white" {}
4.         _ColorMask ("ColorMask", 2D) = "white" {}
5.         _Rotation ("Rotation", Range(0.0, 360.0)) = 0.0
6.     }
7.     SubShader {
8.         Tags { "RenderType"="Opaque" }
9.         Blend One One
10.         LOD 200
11.    
12.         CGPROGRAM
13.         #pragma surface surf Lambert
14.          #pragma vertex vert
15.          sampler2D _FirstTex;
16.          sampler2D _ColorMask;
17.  
18.         struct Input {
19.             float2 uv_FirstTex;
20.             float2 uv2_ColorMask; // uv2 denotes use second UVs.
21.         };
22.         float _Rotation;
23.    
24.         void vert (inout appdata_full v) {
25.             v.texcoord1 = v.texcoord; // copy uvs from texcoord to texcoord1 (aka uv2) before rotation
26.  
27.             float rot = _Rotation / (57.2957795131);
28.             float sinX = sin (rot);
29.             float cosX = cos (rot);
30.             float sinY = sin (rot);
31.             float2x2 rotationMatrix = float2x2( cosX, -sinX, sinY, cosX);
32.             v.texcoord.xy = mul ( v.texcoord.xy, rotationMatrix );
33.         }
34.         void surf (Input IN, inout SurfaceOutput o) {
35.             half4 c = tex2D (_FirstTex, IN.uv_FirstTex);
36.             half4 c2 = tex2D (_ColorMask, IN.uv2_ColorMask);
37.        
38.             o.Albedo = (c.rgb * c2.r); //Dummy code here
39.             o.Alpha = c.a;
40.         }
41.    
42.         ENDCG
43.     }
44.     FallBack "Diffuse"
45. }

 

Ah, thanks a bunch!

New to shader programming here.

 

Nice it works ! But how can i set the rotation pivot to the center of my texture ????
Please help !
Thx
Eviral

 

v.texcoord.xy = mul ( v.texcoord.xy - 0.5, rotationMatrix ) + 0.5;

Should make it rotate around the center of the UV space.

 

Thx ! It works !
But i have a sorting layer problem now
This shader seems to be stronger than the sorting layer specified on my Sprite Renderer

Please help !

Eviral