Unity中，利用shader将NGUI图集大小缩小四倍

最新推荐文章于 2024-01-02 15:50:28 发布

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最新推荐文章于 2024-01-02 15:50:28 发布

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分类专栏： unity 文章标签： NGUI Unity Shader

本文链接：https://blog.youkuaiyun.com/u011627082/article/details/50771969

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本文介绍了一种将带有Alpha通道的ARGB图像拆分为两张RGB图像的方法，并提供了Unity脚本实现。同时，文章还分享了如何通过Shader代码将这两张RGB图像重新合成为一张带Alpha通道的ARGB图像。

如何将ARGB图像（带alpha）分成两张RGB图像（不带alpha,第二张为灰度图），我将导出的alpha图的TextureFormat .RGB24改为TextureFormat .Alpha8，一个通道的Alpha8竟然比3个通道的RGB大，变大两倍。


using System.Collections.Generic;
using System.Linq;
using System.Text;
using UnityEngine;
using UnityEditor;

class TextureSplit : EditorWindow
{
    [ MenuItem ("Assets/Texture Slpit" )]
    static void DoSplit()
    {
        Object [] SelectedTexs = Selection.GetFiltered( typeof (Texture2D ), SelectionMode.Assets);

        foreach (Texture2D Tex in SelectedTexs)
        {

            string TexPath = AssetDatabase .GetAssetPath(Tex);
            TextureImporter TexImporter = AssetImporter .GetAtPath(TexPath) as TextureImporter ;
            TexImporter.isReadable = true ;
            AssetDatabase .ImportAsset(TexPath);


            Texture2D ColorTex = new Texture2D(Tex.width, Tex.height, TextureFormat .RGB24, false );
            ColorTex.SetPixels(Tex.GetPixels());

            string FilePath = AssetDatabase .GetAssetPath(Tex);
            int Pos = FilePath.LastIndexOf( '.');
            FilePath = FilePath.Substring( 0 , Pos);
            FilePath = FilePath + "_color.png" ;

            byte [] bytes = ColorTex.EncodeToPNG();
            System.IO. File .WriteAllBytes(FilePath, bytes);
            {
                AssetDatabase .ImportAsset(FilePath);
                TextureImporter TargetTexImporter = AssetImporter .GetAtPath(FilePath) as TextureImporter ;
                TargetTexImporter.textureType = TexImporter.textureType;
                TargetTexImporter.filterMode = TexImporter.filterMode;
                TargetTexImporter.maxTextureSize = TexImporter.maxTextureSize;
                TargetTexImporter.textureFormat = TextureImporterFormat .AutomaticCompressed;
                AssetDatabase .ImportAsset(FilePath);
            }

            CLogger .Log("Save " + FilePath + " Succeed" );

            Texture2D ALphaTex = new Texture2D(Tex.width, Tex.height, TextureFormat .RGB24, false );
            Color [] Pixels=Tex.GetPixels();
            for (int i = 0; i < Pixels.Length;i++ )
            {
                Pixels[i].r = Pixels[i].a;
                Pixels[i].g = Pixels[i].a;
                Pixels[i].b = Pixels[i].a;
            }
            ALphaTex.SetPixels(Pixels);

            FilePath = AssetDatabase .GetAssetPath(Tex);
            Pos = FilePath.LastIndexOf( '.' );
            FilePath = FilePath.Substring( 0 , Pos);
            FilePath = FilePath + "_alpha.png" ;

            bytes = ALphaTex.EncodeToPNG();
            System.IO. File .WriteAllBytes(FilePath, bytes);
            {
                AssetDatabase .ImportAsset(FilePath);
                TextureImporter TargetTexImporter = AssetImporter .GetAtPath(FilePath) as TextureImporter ;
                TargetTexImporter.textureType = TexImporter.textureType;
                TargetTexImporter.filterMode = TexImporter.filterMode;
                TargetTexImporter.maxTextureSize = TexImporter.maxTextureSize;
                TargetTexImporter.textureFormat = TextureImporterFormat .AutomaticCompressed;
                AssetDatabase .ImportAsset(FilePath);
            }
            CLogger .Log("Save " + FilePath + " Succeed" );
        }
    }
}

</pre><div></div><div><hr /></div><div></div><div><span style="color:rgb(255,0,0)"><span style="font-size:24px">Shader代码，如何将两张RGB图像合并成</span></span><span style="color:rgb(255,0,0)"><span style="font-size:24px">ARGB图像（带alpha）</span></span></div><div><span style="color:rgb(255,0,0)"><span style="font-size:24px"></span></span><pre name="code" class="plain">Shader "Unlit/Transparent Colored SplitTex"
{
     Properties
     {
          _MainTex ("Base (RGB)", 2D) = "black" {}
          _AlphaTex("Alpha (A)", 2D) = "black" {}
     }
    
     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"
    
               struct appdata_t
               {
                    float4 vertex : POSITION;
                    float2 texcoord : TEXCOORD0;
                    fixed4 color : COLOR;
               };
    
               struct v2f
               {
                    float4 vertex : SV_POSITION;
                    half2 texcoord : TEXCOORD0;
                    fixed4 color : COLOR;
                    fixed gray : TEXCOORD1;
               };
    
               sampler2D _MainTex;
               sampler2D _AlphaTex;
               float4 _MainTex_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.gray = dot(v.color, fixed4(1,1,1,0));
                    return o;
               }
                   
               fixed4 frag (v2f i) : COLOR
               {
                   fixed4 col,alpha;
                    col = tex2D(_MainTex, i.texcoord);
                    alpha = tex2D(_AlphaTex, i.texcoord);
                    col.a = alpha.r;

                    if(i.gray == 0)
                    {
                         float grey = dot(col.rgb, float3(0.299, 0.587, 0.114));
                         col.rgb = float3(grey, grey, grey);
                    }
                    else
                    {
                      col = col * i.color;
                    }                   
                    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
               AlphaTest Greater .01
               Blend SrcAlpha OneMinusSrcAlpha
               ColorMaterial AmbientAndDiffuse
              
               SetTexture [_MainTex]
               {
                    Combine Texture * Primary
               }
          }
     }
}