ngui 图片变灰Shader
原理
将彩色图片映射到灰度的的一个过程，我们一般使用的颜色值一般rgb32位每个八位的，在shader里面颜色被转换到[0-1]范围。根据人们的经验得到一个转换的比例是R:0.3 G:0.6 B:0.1 这个大概就是这个范围得到转换效果还不错。（有大神说过图像学第一定律就是看上去是对的，那它就是对的）
关键代码
fixed4 frag(v2f IN) : SV_Target
{
fixed4 color = tex2D(_MainTex, IN.texcoord) * IN.color;
fixed valuergb = color.r * 0.3 + color.g * 0.6 + color.b * 0.1;
color.rgb = valuergb;
return color;
}效果图
对于这个效果用在游戏ui上面还是不错的
NGUI
对于ui我们用的是NGUI 打开NGUI 的UIWidget 发现NGUI的作者已经为自定义材质留好了接口，我们要改的是图片那么打开UISprite找到重写的这个方法加入自己的代码
/// 同时我们看到NGUI在Scroll View下面有一个裁剪效果而这个效果是替换了shader的也就是说我们要使得NGUI正常运行的话需要更改相关的shader。查看代码和NGUI自带shader复制4份，在每一个片段着色器进行一个灰度转换。注意shader的名称被裁减的是前面加了Hidden的
//Shader "Hidden/Unlit/Transparent ColoredGray 1"
fixed4 frag (v2f IN) : SV_Target
{
fixed4 col = tex2D(_MainTex, IN.texcoord) * IN.color;
col.rgb = col.r*0.3+col.g*0.6+col.b*0.1;
return col;
}
最终效果图
最后附上全部更改的Shader
其实就是加上了一句而且其他的都没有动
col.rgb = col.r*0.3+col.g*0.6+col.b*0.1;
Shader "Unlit/Transparent ColoredGray"
{
Properties
{
_MainTex ("Base (RGB), Alpha (A)", 2D) = "black" {}
}
SubShader
{
LOD 200
Tags
{
"Queue" = "Transparent"
"IgnoreProjector" = "True"
"RenderType" = "Transparent"
"DisableBatching" = "True"
}
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"
// Unity 4 compatibility
#ifndef UNITY_VERTEX_INPUT_INSTANCE_ID
#define UNITY_VERTEX_INPUT_INSTANCE_ID
#define UNITY_VERTEX_OUTPUT_STEREO
#define UNITY_SETUP_INSTANCE_ID(v)
#define UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(i)
#define UnityObjectToClipPos(v) mul(UNITY_MATRIX_MVP, v)
#endif
sampler2D _MainTex;
float4 _MainTex_ST;
struct appdata_t
{
float4 vertex : POSITION;
float2 texcoord : TEXCOORD0;
fixed4 color : COLOR;
UNITY_VERTEX_INPUT_INSTANCE_ID
};
struct v2f
{
float4 vertex : SV_POSITION;
half2 texcoord : TEXCOORD0;
fixed4 color : COLOR;
UNITY_VERTEX_OUTPUT_STEREO
};
v2f o;
v2f vert (appdata_t v)
{
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
o.vertex = UnityObjectToClipPos(v.vertex);
o.texcoord = v.texcoord;
o.color = v.color;
return o;
}
fixed4 frag (v2f IN) : SV_Target
{
fixed4 col = tex2D(_MainTex, IN.texcoord) * IN.color;
col.rgb = col.r*0.3+col.g*0.6+col.b*0.1;
return col;
}
ENDCG
}
}
}
Shader "Hidden/Unlit/Transparent ColoredGray 1"
{
Properties
{
_MainTex ("Base (RGB), Alpha (A)", 2D) = "black" {}
}
SubShader
{
LOD 200
Tags
{
"Queue" = "Transparent"
"IgnoreProjector" = "True"
"RenderType" = "Transparent"
"DisableBatching" = "True"
}
Pass
{
Cull Off
Lighting Off
ZWrite Off
Offset -1, -1
Fog { Mode Off }
Blend SrcAlpha OneMinusSrcAlpha
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
// Unity 4 compatibility
#ifndef UNITY_VERTEX_INPUT_INSTANCE_ID
#define UNITY_VERTEX_INPUT_INSTANCE_ID
#define UNITY_VERTEX_OUTPUT_STEREO
#define UNITY_SETUP_INSTANCE_ID(v)
#define UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(i)
#define UnityObjectToClipPos(v) mul(UNITY_MATRIX_MVP, v)
#endif
sampler2D _MainTex;
float4 _ClipRange0 = float4(0.0, 0.0, 1.0, 1.0);
float2 _ClipArgs0 = float2(1000.0, 1000.0);
struct appdata_t
{
float4 vertex : POSITION;
half4 color : COLOR;
float2 texcoord : TEXCOORD0;
UNITY_VERTEX_INPUT_INSTANCE_ID
};
struct v2f
{
float4 vertex : SV_POSITION;
half4 color : COLOR;
float2 texcoord : TEXCOORD0;
float2 worldPos : TEXCOORD1;
UNITY_VERTEX_OUTPUT_STEREO
};
v2f o;
v2f vert (appdata_t v)
{
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
o.vertex = UnityObjectToClipPos(v.vertex);
o.color = v.color;
o.texcoord = v.texcoord;
o.worldPos = v.vertex.xy * _ClipRange0.zw + _ClipRange0.xy;
return o;
}
half4 frag (v2f IN) : SV_Target
{
// Softness factor
float2 factor = (float2(1.0, 1.0) - abs(IN.worldPos)) * _ClipArgs0;
// Sample the texture
half4 col = tex2D(_MainTex, IN.texcoord) * IN.color;
col.rgb = col.r*0.3+col.g*0.6+col.b*0.1;
col.a *= clamp( min(factor.x, factor.y), 0.0, 1.0);
return col;
}
ENDCG
}
}
}
Shader "Hidden/Unlit/Transparent ColoredGray 2"
{
Properties
{
_MainTex ("Base (RGB), Alpha (A)", 2D) = "black" {}
}
SubShader
{
LOD 200
Tags
{
"Queue" = "Transparent"
"IgnoreProjector" = "True"
"RenderType" = "Transparent"
"DisableBatching" = "True"
}
Pass
{
Cull Off
Lighting Off
ZWrite Off
Offset -1, -1
Fog { Mode Off }
Blend SrcAlpha OneMinusSrcAlpha
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
// Unity 4 compatibility
#ifndef UNITY_VERTEX_INPUT_INSTANCE_ID
#define UNITY_VERTEX_INPUT_INSTANCE_ID
#define UNITY_VERTEX_OUTPUT_STEREO
#define UNITY_SETUP_INSTANCE_ID(v)
#define UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(i)
#define UnityObjectToClipPos(v) mul(UNITY_MATRIX_MVP, v)
#endif
sampler2D _MainTex;
float4 _ClipRange0 = float4(0.0, 0.0, 1.0, 1.0);
float4 _ClipArgs0 = float4(1000.0, 1000.0, 0.0, 1.0);
float4 _ClipRange1 = float4(0.0, 0.0, 1.0, 1.0);
float4 _ClipArgs1 = float4(1000.0, 1000.0, 0.0, 1.0);
struct appdata_t
{
float4 vertex : POSITION;
half4 color : COLOR;
float2 texcoord : TEXCOORD0;
UNITY_VERTEX_INPUT_INSTANCE_ID
};
struct v2f
{
float4 vertex : SV_POSITION;
half4 color : COLOR;
float2 texcoord : TEXCOORD0;
float4 worldPos : TEXCOORD1;
UNITY_VERTEX_OUTPUT_STEREO
};
float2 Rotate (float2 v, float2 rot)
{
float2 ret;
ret.x = v.x * rot.y - v.y * rot.x;
ret.y = v.x * rot.x + v.y * rot.y;
return ret;
}
v2f o;
v2f vert (appdata_t v)
{
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
o.vertex = UnityObjectToClipPos(v.vertex);
o.color = v.color;
o.texcoord = v.texcoord;
o.worldPos.xy = v.vertex.xy * _ClipRange0.zw + _ClipRange0.xy;
o.worldPos.zw = Rotate(v.vertex.xy, _ClipArgs1.zw) * _ClipRange1.zw + _ClipRange1.xy;
return o;
}
half4 frag (v2f IN) : SV_Target
{
// First clip region
float2 factor = (float2(1.0, 1.0) - abs(IN.worldPos.xy)) * _ClipArgs0.xy;
float f = min(factor.x, factor.y);
// Second clip region
factor = (float2(1.0, 1.0) - abs(IN.worldPos.zw)) * _ClipArgs1.xy;
f = min(f, min(factor.x, factor.y));
// Sample the texture
half4 col = tex2D(_MainTex, IN.texcoord) * IN.color;
col.rgb = col.r*0.3+col.g*0.6+col.b*0.1;
col.a *= clamp(f, 0.0, 1.0);
return col;
}
ENDCG
}
}
}
Shader "Hidden/Unlit/Transparent ColoredGray 3"
{
Properties
{
_MainTex ("Base (RGB), Alpha (A)", 2D) = "black" {}
}
SubShader
{
LOD 200
Tags
{
"Queue" = "Transparent"
"IgnoreProjector" = "True"
"RenderType" = "Transparent"
"DisableBatching" = "True"
}
Pass
{
Cull Off
Lighting Off
ZWrite Off
Offset -1, -1
Fog { Mode Off }
//ColorMask RGB
Blend SrcAlpha OneMinusSrcAlpha
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
// Unity 4 compatibility
#ifndef UNITY_VERTEX_INPUT_INSTANCE_ID
#define UNITY_VERTEX_INPUT_INSTANCE_ID
#define UNITY_VERTEX_OUTPUT_STEREO
#define UNITY_SETUP_INSTANCE_ID(v)
#define UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(i)
#define UnityObjectToClipPos(v) mul(UNITY_MATRIX_MVP, v)
#endif
sampler2D _MainTex;
float4 _ClipRange0 = float4(0.0, 0.0, 1.0, 1.0);
float4 _ClipArgs0 = float4(1000.0, 1000.0, 0.0, 1.0);
float4 _ClipRange1 = float4(0.0, 0.0, 1.0, 1.0);
float4 _ClipArgs1 = float4(1000.0, 1000.0, 0.0, 1.0);
float4 _ClipRange2 = float4(0.0, 0.0, 1.0, 1.0);
float4 _ClipArgs2 = float4(1000.0, 1000.0, 0.0, 1.0);
struct appdata_t
{
float4 vertex : POSITION;
half4 color : COLOR;
float2 texcoord : TEXCOORD0;
UNITY_VERTEX_INPUT_INSTANCE_ID
};
struct v2f
{
float4 vertex : SV_POSITION;
half4 color : COLOR;
float2 texcoord : TEXCOORD0;
float4 worldPos : TEXCOORD1;
float2 worldPos2 : TEXCOORD2;
UNITY_VERTEX_OUTPUT_STEREO
};
float2 Rotate (float2 v, float2 rot)
{
float2 ret;
ret.x = v.x * rot.y - v.y * rot.x;
ret.y = v.x * rot.x + v.y * rot.y;
return ret;
}
v2f o;
v2f vert (appdata_t v)
{
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
o.vertex = UnityObjectToClipPos(v.vertex);
o.color = v.color;
o.texcoord = v.texcoord;
o.worldPos.xy = v.vertex.xy * _ClipRange0.zw + _ClipRange0.xy;
o.worldPos.zw = Rotate(v.vertex.xy, _ClipArgs1.zw) * _ClipRange1.zw + _ClipRange1.xy;
o.worldPos2 = Rotate(v.vertex.xy, _ClipArgs2.zw) * _ClipRange2.zw + _ClipRange2.xy;
return o;
}
half4 frag (v2f IN) : SV_Target
{
// First clip region
float2 factor = (float2(1.0, 1.0) - abs(IN.worldPos.xy)) * _ClipArgs0.xy;
float f = min(factor.x, factor.y);
// Second clip region
factor = (float2(1.0, 1.0) - abs(IN.worldPos.zw)) * _ClipArgs1.xy;
f = min(f, min(factor.x, factor.y));
// Third clip region
factor = (float2(1.0, 1.0) - abs(IN.worldPos2)) * _ClipArgs2.xy;
f = min(f, min(factor.x, factor.y));
// Sample the texture
half4 col = tex2D(_MainTex, IN.texcoord) * IN.color;
col.rgb = col.r*0.3+col.g*0.6+col.b*0.1;
col.a *= clamp(f, 0.0, 1.0);
return col;
}
ENDCG
}
}
}