Vuforia: it is possible play a Movie texture with alpha in iOS?

问题

I'm trying to use a video with alpha channel, but all I get is the alpha channel as color black.

I'm using the Vuforia video playback example.

I hope I'm not missing any relevant info.

Thanks in advance, any help will be appreciated :)

回答1:

Vuforia plays video by using the built-in system video players (on iOS and Android) by setting them to output to a render texture.

The system players do not support alpha channel video.

You need to apply a chroma-key shader on the render texture to remove say green or purple.

There is some discussion in the vuforia forums:

playing-video-alpha-channel-videosample-demo-project

回答2:

You need to make a "special video" like the pic, in a power of two like: 256x512 format

pic of special video to be used

Then use this custom shader:

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 
  } 
}

Also you can see my post in: http://answers.unity3d.com/questions/833537/how-to-play-alpha-video-in-unity.html#answer-1094012

来源：https://stackoverflow.com/questions/27239136/vuforia-it-is-possible-play-a-movie-texture-with-alpha-in-ios

标签

ios

unity3d

vuforia