How to play Alpha video in unity ?

Questions & Answers
1

hi,

i want to play video in unity with alpha channel.
i tried with this shader to play main video and mask to remove bg.

Shader "MovieWithSeperateAlpha" { 
Properties 
{ 
_MainTex ("Base (RGB)", 2D) = "white" {} 
_Mask ("Culling Mask", 2D) = "white" {} 
_Cutoff ("Cutoff", Range (0,1)) = .5 
}

 SubShader 
 {
     Tags {"Queue"="Transparent"}
 
     ZWrite Off
     Blend SrcAlpha OneMinusSrcAlpha
 
     Pass 
     {    
         CGPROGRAM 
// Upgrade NOTE: excluded shader from OpenGL ES 2.0 because it does not contain a surface program or both vertex and fragment programs.
#pragma exclude_renderers gles
             #pragma fragment frag 
             #include "UnityCG.cginc"  
 
             sampler2D _MainTex; 
             sampler2D _Mask; 
 
             struct v2f 
             { 
                 float4 pos : POSITION; 
                 float4 uv : TEXCOORD0; 
             }; 
 
             half4 frag (v2f i) : COLOR 
             { 
                 half4 color = tex2D(_MainTex, i.uv.xy); 
                 half4 color2 = tex2D(_Mask, i.uv.xy); 
 
                 return half4(color.r, color.g, color.b, color2.r); 
             } 
         ENDCG         
     }    
 }
 
 Fallback "Transparent/Diffuse" 
}

And then i use this script to play both main and mask channel at the same time.

 var maintexture : MovieTexture;
    var mask : MovieTexture;
    
    function Start () 
    { 
    maintexture = renderer.material.GetTexture ("_MainTex"); 
    mask = renderer.material.GetTexture ("_Mask"); 
    
    }
    
    function Update () 
    { 
    	if (Input.GetButtonDown ("Jump")) 
    	{ 
    	
    	maintexture.Play();
    	mask.Play();
    	} 
    	
    }

this code and Shader is working fine but my problem is i am getting bit of delay in playing both movie texture simultaneously.

is there anyway that i can sync both at the same time. or execute play at the same time.

thanx

2

yes, you must use the color and mask in the same video, for example you have two videos 512x512, then you put the color up and the mask down in a 512x1024 video.

57641-ale-sample.png
57641-ale-sample.png310×621 61.3 KB

attached you can find a pic of this kind of video.
the shader used is:
Shader “Custom/alpha1” {

 Properties{ 
      _MainTex("Color (RGB)", 2D) = "white" 
 } 

 SubShader{ 
      Tags{ "Queue" = "Transparent" "RenderType" = "Transparent" } 

      CGPROGRAM 
      #pragma surface surf NoLighting alpha 

      fixed4 LightingNoLighting(SurfaceOutput s, fixed3 lightDir, fixed atten) { 
           fixed4 c; 
           c.rgb = s.Albedo; 
           c.a = s.Alpha; 
           return c; 
      } 

      struct Input { 
           float2 uv_MainTex; 
      }; 

      sampler2D _MainTex; 

      void surf(Input IN, inout SurfaceOutput o) { 
           o.Emission = tex2D(_MainTex, IN.uv_MainTex).rgb; 
                       
          if(IN.uv_MainTex.y <= 0.5){ 
		    o.Alpha=0; 
		  }
		  
		  else{ 
		    o.Alpha = tex2D(_MainTex, float2(IN.uv_MainTex.x, IN.uv_MainTex.y-0.5)).rgb; 
		  }
		  
      } 

      ENDCG 
 }

}

3

if your video has alpha, you can use the FX/Flare shader to do this

4

Really? A picture of a “babe” woman is what you chose to show here? Are we out of pictures?

5

Bump…

How to add different layers of transparent video in Unity3D?