Cutoff + AlphaBlend problems

Hi there,

I'm trying to build a Shader that should allow me to perform a "clock animation" between two textures.
The idea is to have a cutoff value and use a gradient texture to cut the texture but preserving the alpha value of the main texture.

Here is the Shader

Code (csharp):

1.  
2. Shader "MaskedTexture"
3. {
4.    Properties
5.    {
6.       _MainTex ("Base (RGB)", 2D) = "white" {}
7.       _Mask ("Culling Mask", 2D) = "white" {}
8.       _Cutoff ("Alpha cutoff", Range (0,1)) = 0.1
9.    }
10.    
11.    SubShader
12.    {
13.       Tags {"Queue"="Transparent" }
14.       Lighting Off
15.       ZWrite Off
16.       AlphaTest GEqual [_Cutoff]
17.       Blend SrcAlpha OneMinusSrcAlpha    
18.        
19.      BindChannels {
20.         Bind "Color", color
21.         Bind "Vertex", vertex
22.         Bind "TexCoord", texcoord
23.     }    
24.                      
25.       Pass
26.       {                                
27.          SetTexture [_Mask] {combine texture}  
28.          SetTexture [_MainTex] {matrix [_Rotation] combine texture, previous * texture }                                 
29.       }                                  
30.    }
31. }
32.  

And this is what is happening...



The cutted off gradient texture process is being done correctly, the problem is when I merge it, the blending is using the gray texture in the gradient and therefore it appears semitransparent. I suppose i should convert the cutted circle into a full-white-with-no-gray-at-all one, but don't know how!

Anyone please?

 

It doesn't look like you're going about this well. In particular, you haven't shown what you're doing for desaturation, but rendering that, and then a colorized version in another pass, is wasteful. Fixed functions shaders are not good for your effect; it can be done, but your time will be better spent learning enough Cg to do this better.

 

I think I failed to explain everything...
There are TWO images, one is the moon and the other one is the sun. They are separate images and have separate shaders. The front one (the sun) is the one that should "erase" himself in a clock mood, letting you see the back graphic (the moon). If i deactivate blending it renders correctly, but with ugly borders...

 

Hi there,

In the end i found a solution.
The problem was the cutoff was being applied, but also the alpha blending. Removing the "Blend SrcAlpha OneMinusSrcAlpha" was the key to all

Thanks for the help anyway