Strange background color instead of alpha

Unity Engine
1

HI

I am using custom shader which is build from unity standart sprite shader. Instead of transparent background I see orange color. Any ideas what I am doing wrong ? Thank you in advance for help. :slight_smile:

// Unity built-in shader source. Copyright (c) 2016 Unity Technologies. MIT license (see license.txt)

Shader "EgidCustom/Pulsing"
{
    Properties
    {
        [PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
        _Color ("Tint", Color) = (1,1,1,1)
        [MaterialToggle] PixelSnap ("Pixel snap", Float) = 0
        [HideInInspector] _RendererColor ("RendererColor", Color) = (1,1,1,1)
        [HideInInspector] _Flip ("Flip", Vector) = (1,1,1,1)
        [PerRendererData] _AlphaTex ("External Alpha", 2D) = "white" {}
        [PerRendererData] _EnableExternalAlpha ("Enable External Alpha", Float) = 0
    }

    SubShader
    {
        Tags
        {
            "Queue"="Transparent"
            "IgnoreProjector"="True"
            "RenderType"="Transparent"
            "PreviewType"="Plane"
            "CanUseSpriteAtlas"="True"
        }

        Cull Off
        Lighting Off
        ZWrite Off
        Blend One OneMinusSrcAlpha

        Pass
        {
        CGPROGRAM
            #pragma vertex SpriteVert
            #pragma fragment SpriteFrag
            #pragma target 2.0
            #pragma multi_compile_instancing
            #pragma multi_compile _ PIXELSNAP_ON
            #pragma multi_compile _ ETC1_EXTERNAL_ALPHA
            #include "UnitySprites.cginc"

            float4 SpriteFrag(v2f_img i):Color
            {
                fixed4 color = tex2D (_MainTex, i.uv);

                #if ETC1_EXTERNAL_ALPHA
                // get the color from an external texture (usecase: Alpha support for ETC1 on android)
                color.a = tex2D (_AlphaTex, i.uv).r;
                #endif //ETC1_EXTERNAL_ALPHA

                return color;
            }

        ENDCG
        }
    }
}
2

I’m no shader expert, but shouldn’t the blend mode be: Blend **SrcAlpha** OneMinusSrcAlpha

?

1 Like
3

I tryed to replace on with SrcAlpha, but result was same.

4

does it work fine with default sprite shader?

this works for me, had to rename to SpriteFrag2 was getting some duplicate error,

            #pragma fragment SpriteFrag2
            #pragma target 2.0
            #pragma multi_compile_instancing
            #pragma multi_compile _ PIXELSNAP_ON
            #pragma multi_compile _ ETC1_EXTERNAL_ALPHA
            #include "UnitySprites.cginc"

            float4 SpriteFrag2(v2f i):Color
            {
                fixed4 color = tex2D(_MainTex, i.texcoord);
                #if ETC1_EXTERNAL_ALPHA
                    fixed4 alpha = tex2D (_AlphaTex, i.texcoord);
                    color.a = lerp (color.a, alpha.r, _EnableExternalAlpha);
                #endif
                color.rgb*=color.a; // this or either, Blend SrcAlpha OneMinusSrcAlpha
                return color;
            }
1 Like
5

Yes, it works with default sprite shader. Default sprite shader does not have fragment function. (Or is somehow hidden, really dont know how it works :slight_smile: ) Default sprite shader looks like code I posted but withou SpriteFrag function. But I need this function becouse I want do some effects on sprite :slight_smile:

6

Perfect. Thank you very much. For helping me out.