[IOS] AlphaTest issues

Hello,

I'm trying to get a video with an alpha channel running on IOS. I have a plane with the texture playing and I use the following shader that works fine in the editor if set to stand alone. Should i switch the platform to IOS the shader stops working. Since alpha channels arent supported on ios with video. I have a movie with the alpha channel next to it that i sample from.

Adding 'alpha' to the pragma tags will invert my mask

Code (CSharp):

1. Shader "Custom/VideoAlpha" {
2.    Properties {
3.       _MainTex ("Base (RGB)", 2D) = "white" {}
4.       _AlphaOffsetX ("alpha offset x", float) = 0.5
5.       _AlphaOffsetY ("alpha offset y", float) = 0
6.       _Cutoff ("Cutoff", Range (0,1)) = .5
7.    }
8.    SubShader {
9.     Tags { "Queue" = "Transparent" }
10.    AlphaTest Less [_Cutoff]
11.          CGPROGRAM
12.          #pragma surface surf Lambert
13.  
14.          sampler2D _MainTex;
15.          float _AlphaOffsetX;
16.          float _AlphaOffsetY;
17.  
18.          struct Input {
19.             float2 uv_MainTex;
20.          };
21.  
22.          void surf (Input IN, inout SurfaceOutput o) {
23.             half4 c = tex2D (_MainTex, IN.uv_MainTex);
24.             IN.uv_MainTex.x += _AlphaOffsetX;
25.             IN.uv_MainTex.y += _AlphaOffsetY;
26.             half4 d = tex2D (_MainTex, IN.uv_MainTex);
27.             o.Emission = c.rgb;
28.             o.Alpha = (d.r*-1)+1;
29.          }
30.      
31.      
32.          ENDCG
33.  
34.    }
35.  
36.  
37.  
38.    FallBack "Diffuse"
39. }

 

It seems to me the inversion is done right there. Without inversion it's just:

Code (csharp):

1. o.Alpha = d.r;

I'm also wondering a bit why you are using a surface shader for this. Do you need any lighting on the video?

 

d.r makes everything disappear : /. This is a shader posted in a chroma keying thread.

 

It seems to me that d.r should lead to an inverted mask compared to 1-d.r.

Anyway, I noticed the line AlphaTest Less [_Cutoff]. Less mode might not be (properly) supported on iOs. So just use:

Code (csharp):

1.  
2. AlphaTest Greater [_Cutoff]
3.  

Combined with o.Alpha = d.r;

If that doesn't work, just remove the alphatest and change o.Alpha = d.r to:

Code (csharp):

1.  
2. clip(d.r - _Cutoff);
3.  

(Don't forget to add float _Cutoff as input.)

 

Somehow the shader fixed itself or perhaps i misspelt Less as Lesser and it simply broke. But the shader works like a charm now. Thanks Jvo3dc

 

That would be a great addition :

Code (csharp):

1.  
2. SelfHealing Always;
3.