unity安卓游戏优化ETC压缩及Alpha通道处理
在unity中。带有透明通道的图片压缩后。均会出现一定的质量的下降。并且带有透明通道的图片占用内存较大,通过翻阅大量典籍,本人找到并验证了一条可行性解决方案,特分享给大家。具体做法就是将透明通道和图片内容剥离开来。再用4个Shader合并。这样就能减少一半的大小。
1、首先。我们将图片放入texturepacker中。txt类型选unity - json data(txt),导出图片类型选tga。然后导出。如下:
2、接着。我们将tga图片放入PS中。找到图片通道处,并做如下处理:
如上。我们选中Alpha 1.右键。删除该透明通道。然后将图片存储为bmp图片。
然后。我们可以在菜单中后退一步。或者重新打开没有删除透明通道的图片。执行如下操作。
· 选中Alpha1. 按 ctrl + c 复制改透明通道。
· 选中 红 通道。ctrl + v 粘贴通道。绿 蓝 通道执行同样的操作。
· 删除Alpha 1 透明通道。将图片保存为bmp。
将1步骤中导出的txt文件与1)与3)步骤中的bmp格式文件导入unity中。
3、接下来,我们将图片移到Unity中。开始制作图集。然后给图集的材质球赋值我们的shader(Shader代码在最下方)。
4、最后,我们将txt文件与材质球拖放到图集的相应位置,图集制作完成
5、在结尾,将自己编写的shader代码附上:
Shader "Unlit/UIaddETC"
{
Properties
{
_MainTex ("Base (RGB)", 2D) = "white" { }
_AlphaTex("AlphaTex",2D) = "white"{}
}
SubShader
{
LOD 100
Tags
{
"Queue" = "Transparent"
"IgnoreProjector" = "True"
"RenderType" = "Transparent"
}
Cull Off
Lighting Off
ZWrite Off
Fog { Mode Off }
Offset -1, -1
Blend SrcAlpha OneMinusSrcAlpha
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
sampler2D _MainTex;
sampler2D _AlphaTex;
float _AlphaFactor;
struct appdata_t
{
float4 vertex : POSITION;
float2 texcoord : TEXCOORD0;
fixed4 color : COLOR;
};
struct v2f
{
float4 vertex : SV_POSITION;
half2 texcoord : TEXCOORD0;
fixed4 color : COLOR;
};
half4 _MainTex_ST;
half4 _AlphaTex_ST;
v2f vert (appdata_t v)
{
v2f o;
o.vertex = mul (UNITY_MATRIX_MVP, v.vertex);
o.texcoord = v.texcoord;
o.color = v.color;
return o;
}
half4 frag (v2f i) : COLOR
{
half4 texcol = tex2D (_MainTex, i.texcoord);
half4 result = texcol ;
result.a = tex2D(_AlphaTex,i.texcoord)*i.color.a ;
return result;
}
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
}
}
}
}
因为unity ScrollView 会让处理过的图片显示有问题,故参照NGUI自带的shader(例:Transparent Colored,Transparent Colored 1,Transparent Colored 2,Transparent Colored 3,)也对应写了三个shader,在此附上最二个shader如下:
Shader "Hidden/Unlit/UIaddETC 1" {
Properties {
_MainTex ("Base (RGB)", 2D) = "white" { }
_AlphaTex("AlphaTex",2D) = "white"{}
}
SubShader
{
LOD 200
Tags
{
"Queue" = "Transparent+8"
"IgnoreProjector" = "True"
"RenderType" = "Transparent+8"
}
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"
sampler2D _MainTex;
sampler2D _AlphaTex;
float4 _ClipRange0 = float4(0.0, 0.0, 1.0, 1.0);
float2 _ClipArgs0 = float2(1000.0, 1000.0);
float _AlphaFactor;
struct appdata_t
{
float4 vertex : POSITION;
float2 texcoord : TEXCOORD0;
fixed4 color : COLOR;
};
struct v2f
{
float4 vertex : POSITION;
half4 color : COLOR;
float2 texcoord : TEXCOORD0;
float2 worldPos : TEXCOORD1;
};
half4 _MainTex_ST;
half4 _AlphaTex_ST;
v2f vert (appdata_t v)
{
v2f o;
o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
o.texcoord = v.texcoord;
o.color = v.color;
o.worldPos = v.vertex.xy * _ClipRange0.zw + _ClipRange0.xy;
return o;
}
half4 frag (v2f i) : COLOR
{
// Softness factor
float2 factor = (float2(1.0, 1.0) - abs(i.worldPos)) * _ClipArgs0;
half4 texcol = tex2D (_MainTex, i.texcoord) * i.color;
half4 result = texcol ;
result.a *= tex2D(_AlphaTex,i.texcoord)*clamp( min(factor.x, factor.y), 0.0, 1.0);
return result;
}
ENDCG
}
}
SubShader
{
LOD 100
Tags
{
"Queue" = "Transparent+8"
"IgnoreProjector" = "True"
"RenderType" = "Transparent+8"
}
Pass
{
Cull Off
Lighting Off
ZWrite Off
Fog { Mode Off }
ColorMask RGB
Blend SrcAlpha OneMinusSrcAlpha
ColorMaterial AmbientAndDiffuse
SetTexture [_MainTex]
{
Combine Texture * Primary
}
}
}
}
相信聪明的你已经发现了规律,接下去的UIaddETC2与UIaddETC3大家应该也能写出来了,在此就不附代码了。