NGUI 图片变灰

效果图



1、先准备好一个变灰shader。代码如下

Shader "Custom/Gray"
{
Properties
{
_MainTex ("Base (RGB), Alpha (A)", 2D) = "black" {}
}

SubShader
{
LOD 200

Tags
{
"Queue" = "Transparent"
"IgnoreProjector" = "True"
"RenderType" = "Transparent"
}

Pass
{
Cull Off
Lighting Off
ZWrite Off
Fog { Mode Off }
Offset -1, -1
Blend SrcAlpha OneMinusSrcAlpha

CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"

sampler2D _MainTex;
float4 _MainTex_ST;

struct appdata_t
{
float4 vertex : POSITION;
float2 texcoord : TEXCOORD0;
fixed4 color : COLOR;
};

struct v2f
{
float4 vertex : SV_POSITION;
half2 texcoord : TEXCOORD0;
fixed4 color : COLOR;
};

v2f o;

v2f vert (appdata_t v)
{
o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
o.texcoord = v.texcoord;
o.color = v.color;
return o;
}

fixed4 frag (v2f IN) : COLOR
{
float4 col =tex2D(_MainTex, IN.texcoord) * IN.color;
float grey = dot(col.rgb, float3(0.299, 0.587, 0.114));
col.rgb = float3(grey, grey, grey);

return col;
}
ENDCG
}
}

SubShader
{
LOD 100

Tags
{
"Queue" = "Transparent"
"IgnoreProjector" = "True"
"RenderType" = "Transparent"
}

Pass
{
Cull Off
Lighting Off
ZWrite Off
Fog { Mode Off }
Offset -1, -1
ColorMask RGB
Blend SrcAlpha OneMinusSrcAlpha
ColorMaterial AmbientAndDiffuse

SetTexture [_MainTex]
{
Combine Texture * Primary
}
}
}
}

　　

2、制作一个atlas图集prefab

　　在Project里选择几个纹理右键->Open Atlas Maker->New->Create

3、修改prefab材质

　　点击刚刚生成的atlas图集prefab->Material->导航到Project中我们刚生成的atlas图集prefab所使用的材质->把shader改成Custom/Cray(这个shader就是我们上面那个shader的名字)

4、设置到UISprite下看看