Alpha Diffuse Surface Shader issue

Questions & Answers
1

Hi!

I’m trying to build some custom shaders for my next title but I bumped into some problems.
As you can see on picture below:

top left: looks relatively fine

other pictures shows issues with sorting rendered mesh. (whole “ground” is a single mesh)

[12739-strange+effect.jpg|12739]

for makign screenshot I have used a bit modified shader:
Shader “Transparent/Diffuse” {
Properties {
_Color (“Main Color”, Color) = (1,1,1,1)
_MainTex (“Base (RGB) Trans (A)”, 2D) = “white” {}
}

SubShader {
	Tags {"Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent"}
	LOD 200

CGPROGRAM
#pragma surface surf Lambert alpha

sampler2D _MainTex;
fixed4 _Color;

struct Input {
	float2 uv_MainTex;
};

void surf (Input IN, inout SurfaceOutput o) {
	fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
	o.Albedo = c.rgb;
	o.Alpha = c.a;
}
ENDCG
}

Fallback "Transparent/VertexLit"
}

Bud I get exactly same issue with native version of this shader (its default Alpha-Diffuse.shader avaliable with unity)

issue dissapears as soon as I use:

    #pragma surface surf Lambert

instead of

    #pragma surface surf Lambert alpha

but I simply need to be able use transparency in shader.

Any help would be much appreciated.

Thank you

2

Once you add “alpha” it disables writing into ZBuffer and then it can overdraw itself. I think in your case you don’t need alpha-blendting, but alpha-testing. There is a pragma for that: alphatest:VariableName (Unity - Manual: Writing Surface Shaders).