移除Unity工程里所有图片的Alpha通道
发表于2017-11-03
为测试Untiy工程里Texture的Alpha对性能的压力，需要临时移除Unity工程里所有图片的Alpha通道，做测试对比。考虑到有些人没有这方面经验，为此，这里给大家分享一个移除移除Unity工程里所有图片的Alpha通道基本的技巧，当图片不存在Alpha通道时，就不需要处理，如何判断图片是否存在Alpha通道呢，Unity不存在直接的接口。但可以这么干：
1.
ti.textureFormat = TextureImporterFormat.AutomaticTruecolor;
AssetDatabase.ImportAsset(_relativeAssetPath);
2.
static bool IsNoAlphaTexture(Texture2D texture)
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return texture.format == TextureFormat.RGB24;
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代码如下：
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using UnityEditor;
using System.IO;
using System.Reflection;
public class RemoveAlphaChanel
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[MenuItem("TextureTest/Remove Texture Alpha Chanel")]
static void ModifyTextures()
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Debug.Log("Start Removing Alpha Chanel.");
string[] paths = Directory.GetFiles(Application.dataPath, "*.*", SearchOption.AllDirectories);
foreach (string path in paths)
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if (!string.IsNullOrEmpty(path) && IsTextureFile(path)) //full name
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RemoveTextureAlphaChanel(path);
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AssetDatabase.Refresh(); //Refresh to ensure new generated RBA and Alpha textures shown in Unity as well as the meta file
Debug.Log("Finish Removing Alpha Chanel.");
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[MenuItem("TextureTest/LimitTextureSizeTo128")]
static void LimitTextures()
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Debug.Log("Start Limit Textures.");
string[] paths = Directory.GetFiles(Application.dataPath, "*.*", SearchOption.AllDirectories);
foreach (string path in paths)
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if (!string.IsNullOrEmpty(path) && IsTextureFile(path)) //full name
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try
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string assetRelativePath = GetRelativeAssetPath(path);
ReImportAsset(assetRelativePath);
Debug.Log("Limit Texture: " + assetRelativePath);
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catch
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Debug.LogError("ReImport Texture failed: " + GetRelativeAssetPath(path));
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AssetDatabase.Refresh(); //Refresh to ensure new generated RBA and Alpha textures shown in Unity as well as the meta file
Debug.Log("Finish Limit Textures.");
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#region process texture
static void RemoveTextureAlphaChanel(string _texPath)
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string assetRelativePath = GetRelativeAssetPath(_texPath);
SetTextureReadableEx(assetRelativePath); //set readable flag and set textureFormat TrueColor
Texture2D sourcetex = Resources.LoadAssetAtPath(assetRelativePath, typeof(Texture2D)) as Texture2D; //not just the textures under Resources file
if (!sourcetex)
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Debug.LogError("Load Texture Failed : " + assetRelativePath);
return;
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if (IsNoAlphaTexture(sourcetex))
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Debug.Log("pass. no Alpha texture: " + assetRelativePath);
return;
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#region Get origion Mipmap Setting
TextureImporter ti = null;
try
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ti = (TextureImporter)TextureImporter.GetAtPath(assetRelativePath);
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catch
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Debug.LogError("Load Texture failed: " + assetRelativePath);
return;
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if (ti == null)
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return;
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bool bGenerateMipMap = ti.mipmapEnabled; //same with the texture import setting
#endregion
Texture2D rgbTex = new Texture2D(sourcetex.width, sourcetex.height, TextureFormat.RGB24, bGenerateMipMap);
rgbTex.SetPixels(sourcetex.GetPixels());
rgbTex.Apply();
byte[] bytes = rgbTex.EncodeToPNG();
File.WriteAllBytes(assetRelativePath, bytes);
ReImportAsset(assetRelativePath, sourcetex.width, sourcetex.height);
Debug.Log("Succeed Removing Alpha : " + assetRelativePath);
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static bool IsNoAlphaTexture(Texture2D texture)
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return texture.format == TextureFormat.RGB24;
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static void SetTextureReadableEx(string _relativeAssetPath) //set readable flag and set textureFormat TrueColor
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TextureImporter ti = null;
try
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ti = (TextureImporter)TextureImporter.GetAtPath(_relativeAssetPath);
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catch
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Debug.LogError("Load Texture failed: " + _relativeAssetPath);
return;
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if (ti == null)
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return;
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ti.isReadable = true;
ti.textureFormat = TextureImporterFormat.AutomaticTruecolor; //this is essential for departing Textures for ETC1. No compression format for following operation.
AssetDatabase.ImportAsset(_relativeAssetPath);
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static void ReImportAsset(string path)
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TextureImporter importer = null;
try
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importer = (TextureImporter)TextureImporter.GetAtPath(path);
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catch
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Debug.LogError("Load Texture failed: " + path);
return;
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if (importer == null)
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return;
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importer.maxTextureSize = 128;
importer.anisoLevel = 0;
importer.isReadable = false; //increase memory cost if readable is true
importer.textureFormat = TextureImporterFormat.AutomaticCompressed;
AssetDatabase.ImportAsset(path);
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static void ReImportAsset(string path, int width, int height)
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try
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AssetDatabase.ImportAsset(path);
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catch
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Debug.LogError("Import Texture failed: " + path);
return;
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TextureImporter importer = null;
try
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importer = (TextureImporter)TextureImporter.GetAtPath(path);
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catch
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Debug.LogError("Load Texture failed: " + path);
return;
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if (importer == null)
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return;
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importer.maxTextureSize = Mathf.Max(width, height);
importer.anisoLevel = 0;
importer.isReadable = false; //increase memory cost if readable is true
importer.textureFormat = TextureImporterFormat.AutomaticCompressed;
importer.textureType = TextureImporterType.Image;
if (path.Contains("/UI/"))
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importer.textureType = TextureImporterType.GUI;
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AssetDatabase.ImportAsset(path);
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#endregion
#region string or path helper
static bool IsTextureFile(string _path)
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string path = _path.ToLower();
return path.EndsWith(".psd") || path.EndsWith(".tga") || path.EndsWith(".png") || path.EndsWith(".jpg") || path.EndsWith(".bmp") || path.EndsWith(".tif") || path.EndsWith(".gif");
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static string GetRelativeAssetPath(string _fullPath)
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_fullPath = GetRightFormatPath(_fullPath);
int idx = _fullPath.IndexOf("Assets");
string assetRelativePath = _fullPath.Substring(idx);
return assetRelativePath;
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static string GetRightFormatPath(string _path)
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return _path.Replace("\\", "/");
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static string GetFilePostfix(string _filepath) //including '.' eg ".tga", ".png", no".dds"
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string postfix = "";
int idx = _filepath.LastIndexOf('.');
if (idx > 0 && idx < _filepath.Length)
postfix = _filepath.Substring(idx, _filepath.Length - idx);
return postfix;
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#endregion
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