unity 自动删除未引用的Assets下的资源

随着时间的堆积，项目中Assets文件夹下的资源会变得越来越繁杂，有些贴图、材质啥的可能压根没有使用过，但是又不敢轻易去删除。

这里分享两个插件，用于管理这些资源。

一、ResourceChecker

这个插件的强大之处就在于它能够查找当前场景中的所有引用个资源，并快速定位，然后把未定位到的资源手动删掉就行了。

代码

// Resource Checker
// (c) 2012 Simon Oliver / HandCircus / hello@handcircus.com
// (c) 2015 Brice Clocher / Mangatome / hello@mangatome.net
// Public domain, do with whatever you like, commercial or not
// This comes with no warranty, use at your own risk!
// https://github.com/handcircus/Unity-Resource-Checker

using System;
using System.Linq;
using UnityEngine;
using UnityEngine.UI;
using UnityEditor;
using System.Collections.Generic;
using System.Reflection;
using Object = UnityEngine.Object;

public class TextureDetails : IEquatable<TextureDetails>
{
    public bool isCubeMap;
    public int memSizeKB;
    public Texture texture;
    public TextureFormat format;
    public int mipMapCount;
    public List<Object> FoundInMaterials=new List<Object>();
    public List<Object> FoundInRenderers=new List<Object>();
    public List<Object> FoundInAnimators = new List<Object>();
    public List<Object> FoundInScripts = new List<Object>();
    public List<Object> FoundInGraphics = new List<Object>();
    public bool isSky;
    public bool instance;
    public bool isgui;
    public TextureDetails()
    {

    }

    public bool Equals(TextureDetails other)
    {
        return texture != null && other.texture != null &&
            texture.GetNativeTexturePtr() == other.texture.GetNativeTexturePtr();
    }

    public override int GetHashCode()
    {
        return (int)texture.GetNativeTexturePtr();
    }

    public override bool Equals(object obj)
    {
        return Equals(obj as TextureDetails);
    }
};

public class MaterialDetails
{

    public Material material;

    public List<Renderer> FoundInRenderers=new List<Renderer>();
    public List<Graphic> FoundInGraphics=new List<Graphic>();
    public bool instance;
    public bool isgui;
    public bool isSky;

    public MaterialDetails()
    {
        instance = false;
        isgui = false;
        isSky = false;
    }
};

public class MeshDetails
{

    public Mesh mesh;

    public List<MeshFilter> FoundInMeshFilters=new List<MeshFilter>();
    public List<SkinnedMeshRenderer> FoundInSkinnedMeshRenderer=new List<SkinnedMeshRenderer>();
    public bool instance;

    public MeshDetails()
    {
        instance = false;
    }
};

public class MissingGraphic{
    public Transform Object;
    public string type;
    public string name;
}

public class ResourceChecker : EditorWindow {


    string[] inspectToolbarStrings = {"Textures", "Materials","Meshes"};
    string[] inspectToolbarStrings2 = {"Textures", "Materials","Meshes", "Missing"};

    enum InspectType 
    {
        Textures,Materials,Meshes,Missing
    };

    bool IncludeDisabledObjects=true;
    bool IncludeSpriteAnimations=true;
    bool IncludeScriptReferences=true;
    bool IncludeGuiElements=true;
    bool thingsMissing = false;

    InspectType ActiveInspectType=InspectType.Textures;

    float ThumbnailWidth=40;
    float ThumbnailHeight=40;

    List<TextureDetails> ActiveTextures=new List<TextureDetails>();
    List<MaterialDetails> ActiveMaterials=new List<MaterialDetails>();
    List<MeshDetails> ActiveMeshDetails=new List<MeshDetails>();
    List<MissingGraphic> MissingObjects = new List<MissingGraphic> ();

    Vector2 textureListScrollPos=new Vector2(0,0);
    Vector2 materialListScrollPos=new Vector2(0,0);
    Vector2 meshListScrollPos=new Vector2(0,0);
    Vector2 missingListScrollPos = new Vector2 (0,0);

    int TotalTextureMemory=0;
    int TotalMeshVertices=0;

    bool ctrlPressed=false;

    static int MinWidth=475;
    Color defColor;

    bool collectedInPlayingMode;

    [MenuItem ("Window/Resource Checker")]
    static void Init ()
    {  
        ResourceChecker window = (ResourceChecker) EditorWindow.GetWindow (typeof (ResourceChecker));
        window.CheckResources();
        window.minSize=new Vector2(MinWidth,475);
    }

    void OnGUI ()
    {
        defColor = GUI.color;
        IncludeDisabledObjects = GUILayout.Toggle(IncludeDisabledObjects, "Include disabled objects", GUILayout.Width(300));
        IncludeSpriteAnimations = GUILayout.Toggle(IncludeSpriteAnimations, "Look in sprite animations", GUILayout.Width(300));
        GUI.color = new Color (0.8f, 0.8f, 1.0f, 1.0f);
        IncludeScriptReferences = GUILayout.Toggle(IncludeScriptReferences, "Look in behavior fields", GUILayout.Width(300));
        GUI.color = new Color (1.0f, 0.95f, 0.8f, 1.0f);
        IncludeGuiElements = GUILayout.Toggle(IncludeGuiElements, "Look in GUI elements", GUILayout.Width(300));
        GUI.color = defColor;
        GUILayout.BeginArea(new Rect(position.width-85,5,100,65));
        if (GUILayout.Button("Calculate",GUILayout.Width(80), GUILayout.Height(40)))
            CheckResources();
        if (GUILayout.Button("CleanUp",GUILayout.Width(80), GUILayout.Height(20)))
            Resources.UnloadUnusedAssets();
        GUILayout.EndArea();
        RemoveDestroyedResources();

        GUILayout.Space(30);
        if (thingsMissing == true) {
            EditorGUI.HelpBox (new Rect(8,75,300,25),"Some GameObjects are missing graphical elements.", MessageType.Error);
        }
        GUILayout.BeginHorizontal();
        GUILayout.Label("Textures "+ActiveTextures.Count+" - "+FormatSizeString(TotalTextureMemory));
        GUILayout.Label("Materials "+ActiveMaterials.Count);
        GUILayout.Label("Meshes "+ActiveMeshDetails.Count+" - "+TotalMeshVertices+" verts");
        GUILayout.EndHorizontal();
        if (thingsMissing == true) {
            ActiveInspectType = (InspectType)GUILayout.Toolbar ((int)ActiveInspectType, inspectToolbarStrings2);
        } else {
            ActiveInspectType = (InspectType)GUILayout.Toolbar ((int)ActiveInspectType, inspectToolbarStrings);
        }

        ctrlPressed=Event.current.control || Event.current.command;

        switch (ActiveInspectType)
        {
        case InspectType.Textures:
            ListTextures();
            break;
        case InspectType.Materials:
            ListMaterials();
            break;
        case InspectType.Meshes:
            ListMeshes();
            break;
        case InspectType.Missing:
            ListMissing();
            break;
        }
    }

    private void RemoveDestroyedResources()
    {
        if (collectedInPlayingMode != Application.isPlaying)
        {
            ActiveTextures.Clear();
            ActiveMaterials.Clear();
            ActiveMeshDetails.Clear();
            MissingObjects.Clear ();
            thingsMissing = false;
            collectedInPlayingMode = Application.isPlaying;
        }
        
        ActiveTextures.RemoveAll(x => !x.texture);
        ActiveTextures.ForEach(delegate(TextureDetails obj) {
            obj.FoundInAnimators.RemoveAll(x => !x);
            obj.FoundInMaterials.RemoveAll(x => !x);
            obj.FoundInRenderers.RemoveAll(x => !x);
            obj.FoundInScripts.RemoveAll(x => !x);
            obj.FoundInGraphics.RemoveAll(x => !x);
        });

        ActiveMaterials.RemoveAll(x => !x.material);
        ActiveMaterials.ForEach(delegate(MaterialDetails obj) {
            obj.FoundInRenderers.RemoveAll(x => !x);
            obj.FoundInGraphics.RemoveAll(x => !x);
        });

        ActiveMeshDetails.RemoveAll(x => !x.mesh);
        ActiveMeshDetails.ForEach(delegate(MeshDetails obj) {
            obj.FoundInMeshFilters.RemoveAll(x => !x);
            obj.FoundInSkinnedMeshRenderer.RemoveAll(x => !x);
        });

        TotalTextureMemory = 0;
        foreach (TextureDetails tTextureDetails in ActiveTextures) TotalTextureMemory += tTextureDetails.memSizeKB;

        TotalMeshVertices = 0;
        foreach (MeshDetails tMeshDetails in ActiveMeshDetails) TotalMeshVertices += tMeshDetails.mesh.vertexCount;
    }

    int GetBitsPerPixel(TextureFormat format)
    {
        switch (format)
        {
        case TextureFormat.Alpha8: //     Alpha-only texture format.
            return 8;
        case TextureFormat.ARGB4444: //     A 16 bits/pixel texture format. Texture stores color with an alpha channel.
            return 16;
        case TextureFormat.RGBA4444: //     A 16 bits/pixel texture format.
            return 16;
        case TextureFormat.RGB24:    // A color texture format.
            return 24;
        case TextureFormat.RGBA32:    //Color with an alpha channel texture format.
            return 32;
        case TextureFormat.ARGB32:    //Color with an alpha channel texture format.
            return 32;
        case TextureFormat.RGB565:    //     A 16 bit color texture format.
            return 16;
        case TextureFormat.DXT1:    // Compressed color texture format.
            return 4;
        case TextureFormat.DXT5:    // Compressed color with alpha channel texture format.
            return 8;
            /*
            case TextureFormat.WiiI4:    // Wii texture format.
            case TextureFormat.WiiI8:    // Wii texture format. Intensity 8 bit.
            case TextureFormat.WiiIA4:    // Wii texture format. Intensity + Alpha 8 bit (4 + 4).
            case TextureFormat.WiiIA8:    // Wii texture format. Intensity + Alpha 16 bit (8 + 8).
            case TextureFormat.WiiRGB565:    // Wii texture format. RGB 16 bit (565).
            case TextureFormat.WiiRGB5A3:    // Wii texture format. RGBA 16 bit (4443).
            case TextureFormat.WiiRGBA8:    // Wii texture format. RGBA 32 bit (8888).
            case TextureFormat.WiiCMPR:    //     Compressed Wii texture format. 4 bits/texel, ~RGB8A1 (Outline alpha is not currently supported).
                return 0;  //Not supported yet
            */
        case TextureFormat.PVRTC_RGB2://     PowerVR (iOS) 2 bits/pixel compressed color texture format.
            return 2;
        case TextureFormat.PVRTC_RGBA2://     PowerVR (iOS) 2 bits/pixel compressed with alpha channel texture format
            return 2;
        case TextureFormat.PVRTC_RGB4://     PowerVR (iOS) 4 bits/pixel compressed color texture format.
            return 4;
        case TextureFormat.PVRTC_RGBA4://     PowerVR (iOS) 4 bits/pixel compressed with alpha channel texture format
            return 4;
        case TextureFormat.ETC_RGB4://     ETC (GLES2.0) 4 bits/pixel compressed RGB texture format.
            return 4;
        case TextureFormat.ATC_RGB4://     ATC (ATITC) 4 bits/pixel compressed RGB texture format.
            return 4;
        case TextureFormat.ATC_RGBA8://     ATC (ATITC) 8 bits/pixel compressed RGB texture format.
            return 8;
        case TextureFormat.BGRA32://     Format returned by iPhone camera
            return 32;
            #if !UNITY_5 && !UNITY_5_3_OR_NEWER
            case TextureFormat.ATF_RGB_DXT1://     Flash-specific RGB DXT1 compressed color texture format.
            case TextureFormat.ATF_RGBA_JPG://     Flash-specific RGBA JPG-compressed color texture format.
            case TextureFormat.ATF_RGB_JPG://     Flash-specific RGB JPG-compressed color texture format.
            return 0; //Not supported yet  
            #endif
        }
        return 0;
    }

    int CalculateTextureSizeBytes(Texture tTexture)
    {

        int tWidth=tTexture.width;
        int tHeight=tTexture.height;
        if (tTexture is Texture2D)
        {
            Texture2D tTex2D=tTexture as Texture2D;
            int bitsPerPixel=GetBitsPerPixel(tTex2D.format);
            int mipMapCount=tTex2D.mipmapCount;
            int mipLevel=1;
            int tSize=0;
            while (mipLevel<=mipMapCount)
            {
                tSize+=tWidth*tHeight*bitsPerPixel/8;
                tWidth=tWidth/2;
                tHeight=tHeight/2;
                mipLevel++;
            }
            return tSize;
        }
        if (tTexture is Texture2DArray)
        {
            Texture2DArray tTex2D=tTexture as Texture2DArray;
            int bitsPerPixel=GetBitsPerPixel(tTex2D.format);
            int mipMapCount=10;
            int mipLevel=1;
            int tSize=0;
            while (mipLevel<=mipMapCount)
            {
                tSize+=tWidth*tHeight*bitsPerPixel/8;
                tWidth=tWidth/2;
                tHeight=tHeight/2;
                mipLevel++;
            }
            return tSize*((Texture2DArray)tTex2D).depth;
        }
        if (tTexture is Cubemap) {
            Cubemap tCubemap = tTexture as Cubemap;
            int bitsPerPixel = GetBitsPerPixel (tCubemap.format);
            return tWidth * tHeight * 6 * bitsPerPixel / 8;
        }
        return 0;
    }


    void SelectObject(Object selectedObject,bool append)
    {
        if (append)
        {
            List<Object> currentSelection=new List<Object>(Selection.objects);
            // Allow toggle selection
            if (currentSelection.Contains(selectedObject)) currentSelection.Remove(selectedObject);
            else currentSelection.Add(selectedObject);

            Selection.objects=currentSelection.ToArray();
        }
        else Selection.activeObject=selectedObject;
    }

    void SelectObjects(List<Object> selectedObjects,bool append)
    {
        if (append)
        {
            List<Object> currentSelection=new List<Object>(Selection.objects);
            currentSelection.AddRange(selectedObjects);
            Selection.objects=currentSelection.ToArray();
        }
        else Selection.objects=selectedObjects.ToArray();
    }

    void ListTextures()
    {
        textureListScrollPos = EditorGUILayout.BeginScrollView(textureListScrollPos);

        foreach (TextureDetails tDetails in ActiveTextures)
        {            

            GUILayout.BeginHorizontal ();
            Texture tex = new Texture();
            tex = tDetails.texture;
            if(tDetails.texture.GetType() == typeof(Texture2DArray) || tDetails.texture.GetType() == typeof(Cubemap)){
                tex = AssetPreview.GetMiniThumbnail(tDetails.texture);
            }
            GUILayout.Box(tex, GUILayout.Width(ThumbnailWidth), GUILayout.Height(ThumbnailHeight));

            if (tDetails.instance == true)
                GUI.color = new Color (0.8f, 0.8f, defColor.b, 1.0f);
            if (tDetails.isgui == true)
                GUI.color = new Color (defColor.r, 0.95f, 0.8f, 1.0f);
            if (tDetails.isSky)
                GUI.color = new Color (0.9f, defColor.g, defColor.b, 1.0f);
            if(GUILayout.Button(tDetails.texture.name,GUILayout.Width(150)))
            {
                SelectObject(tDetails.texture,ctrlPressed);
            }
            GUI.color = defColor;

            string sizeLabel=""+tDetails.texture.width+"x"+tDetails.texture.height;
            if (tDetails.isCubeMap) sizeLabel+="x6";
            if (tDetails.texture.GetType () == typeof(Texture2DArray))
                sizeLabel+= "[]
" + ((Texture2DArray)tDetails.texture).depth+"depths";
            sizeLabel+=" - "+tDetails.mipMapCount+"mip
"+FormatSizeString(tDetails.memSizeKB)+" - "+tDetails.format;

            GUILayout.Label (sizeLabel,GUILayout.Width(120));

            if(GUILayout.Button(tDetails.FoundInMaterials.Count+" Mat",GUILayout.Width(50)))
            {
                SelectObjects(tDetails.FoundInMaterials,ctrlPressed);
            }

            HashSet<Object> FoundObjects = new HashSet<Object>();
            foreach (Renderer renderer in tDetails.FoundInRenderers) FoundObjects.Add(renderer.gameObject);
            foreach (Animator animator in tDetails.FoundInAnimators) FoundObjects.Add(animator.gameObject);
            foreach (Graphic graphic in tDetails.FoundInGraphics) FoundObjects.Add(graphic.gameObject);
            foreach (MonoBehaviour script in tDetails.FoundInScripts) FoundObjects.Add(script.gameObject);
            if (GUILayout.Button(FoundObjects.Count+" GO",GUILayout.Width(50)))
            {
                SelectObjects(new List<Object>(FoundObjects),ctrlPressed);
            }

            GUILayout.EndHorizontal();    
        }
        if (ActiveTextures.Count>0)
        {
            EditorGUILayout.Space();
            GUILayout.BeginHorizontal ();
            //GUILayout.Box(" ",GUILayout.Width(ThumbnailWidth),GUILayout.Height(ThumbnailHeight));
            if(GUILayout.Button("Select 
 All",GUILayout.Width(ThumbnailWidth*2)))
            {
                List<Object> AllTextures=new List<Object>();
                foreach (TextureDetails tDetails in ActiveTextures) AllTextures.Add(tDetails.texture);
                SelectObjects(AllTextures,ctrlPressed);
            }
            EditorGUILayout.EndHorizontal();
        }
        EditorGUILayout.EndScrollView();
    }

    void ListMaterials()
    {
        materialListScrollPos = EditorGUILayout.BeginScrollView(materialListScrollPos);

        foreach (MaterialDetails tDetails in ActiveMaterials)
        {            
            if (tDetails.material!=null)
            {
                GUILayout.BeginHorizontal ();

                GUILayout.Box(AssetPreview.GetAssetPreview(tDetails.material), GUILayout.Width(ThumbnailWidth), GUILayout.Height(ThumbnailHeight));

                if (tDetails.instance == true)
                    GUI.color = new Color (0.8f, 0.8f, defColor.b, 1.0f);
                if (tDetails.isgui == true)
                    GUI.color = new Color (defColor.r, 0.95f, 0.8f, 1.0f);
                if (tDetails.isSky)
                    GUI.color = new Color (0.9f, defColor.g, defColor.b, 1.0f);
                if(GUILayout.Button(tDetails.material.name,GUILayout.Width(150)))
                {
                    SelectObject(tDetails.material,ctrlPressed);
                }
                GUI.color = defColor;

                string shaderLabel = tDetails.material.shader != null ? tDetails.material.shader.name : "no shader";
                GUILayout.Label (shaderLabel, GUILayout.Width(200));

                if(GUILayout.Button((tDetails.FoundInRenderers.Count + tDetails.FoundInGraphics.Count) +" GO",GUILayout.Width(50)))
                {
                    List<Object> FoundObjects=new List<Object>();
                    foreach (Renderer renderer in tDetails.FoundInRenderers) FoundObjects.Add(renderer.gameObject);
                    foreach (Graphic graphic in tDetails.FoundInGraphics) FoundObjects.Add(graphic.gameObject);
                    SelectObjects(FoundObjects,ctrlPressed);
                }


                GUILayout.EndHorizontal();    
            }
        }
        EditorGUILayout.EndScrollView();        
    }

    void ListMeshes()
    {
        meshListScrollPos = EditorGUILayout.BeginScrollView(meshListScrollPos);

        foreach (MeshDetails tDetails in ActiveMeshDetails)
        {            
            if (tDetails.mesh!=null)
            {
                GUILayout.BeginHorizontal ();
                string name = tDetails.mesh.name;
                if (name == null || name.Count() < 1)
                    name = tDetails.FoundInMeshFilters[0].gameObject.name;
                if (tDetails.instance == true)
                    GUI.color = new Color (0.8f, 0.8f, defColor.b, 1.0f);
                if(GUILayout.Button(name,GUILayout.Width(150)))
                {
                    SelectObject(tDetails.mesh,ctrlPressed);
                }
                GUI.color = defColor;
                string sizeLabel=""+tDetails.mesh.vertexCount+" vert";

                GUILayout.Label (sizeLabel,GUILayout.Width(100));


                if(GUILayout.Button(tDetails.FoundInMeshFilters.Count + " GO",GUILayout.Width(50)))
                {
                    List<Object> FoundObjects=new List<Object>();
                    foreach (MeshFilter meshFilter in tDetails.FoundInMeshFilters) FoundObjects.Add(meshFilter.gameObject);
                    SelectObjects(FoundObjects,ctrlPressed);
                }
                if (tDetails.FoundInSkinnedMeshRenderer.Count > 0) {
                    if (GUILayout.Button (tDetails.FoundInSkinnedMeshRenderer.Count + " skinned mesh GO", GUILayout.Width (140))) {
                        List<Object> FoundObjects = new List<Object> ();
                        foreach (SkinnedMeshRenderer skinnedMeshRenderer in tDetails.FoundInSkinnedMeshRenderer)
                            FoundObjects.Add (skinnedMeshRenderer.gameObject);
                        SelectObjects (FoundObjects, ctrlPressed);
                    }
                } else {
                    GUI.color = new Color (defColor.r, defColor.g, defColor.b, 0.5f);
                    GUILayout.Label("   0 skinned mesh");
                    GUI.color = defColor;
                }


                GUILayout.EndHorizontal();    
            }
        }
        EditorGUILayout.EndScrollView();        
    }

    void ListMissing(){
        missingListScrollPos = EditorGUILayout.BeginScrollView(missingListScrollPos);
        foreach (MissingGraphic dMissing in MissingObjects) {
            GUILayout.BeginHorizontal ();
            if (GUILayout.Button (dMissing.name, GUILayout.Width (150)))
                SelectObject (dMissing.Object, ctrlPressed);
            GUILayout.Label ("missing ", GUILayout.Width(48));
            switch (dMissing.type) {
            case "mesh":
                GUI.color = new Color (0.8f, 0.8f, defColor.b, 1.0f);
                break;
            case "sprite":
                GUI.color = new Color (defColor.r, 0.8f, 0.8f, 1.0f);
                break;
            case "material":
                GUI.color = new Color (0.8f, defColor.g, 0.8f, 1.0f);
                break;
            }
            GUILayout.Label (dMissing.type);
            GUI.color = defColor;
            GUILayout.EndHorizontal ();
        }
        EditorGUILayout.EndScrollView();
    }

    string FormatSizeString(int memSizeKB)
    {
        if (memSizeKB<1024) return ""+memSizeKB+"k";
        else
        {
            float memSizeMB=((float)memSizeKB)/1024.0f;
            return memSizeMB.ToString("0.00")+"Mb";
        }
    }


    TextureDetails FindTextureDetails(Texture tTexture)
    {
        foreach (TextureDetails tTextureDetails in ActiveTextures)
        {
            if (tTextureDetails.texture==tTexture) return tTextureDetails;
        }
        return null;

    }

    MaterialDetails FindMaterialDetails(Material tMaterial)
    {
        foreach (MaterialDetails tMaterialDetails in ActiveMaterials)
        {
            if (tMaterialDetails.material==tMaterial) return tMaterialDetails;
        }
        return null;

    }

    MeshDetails FindMeshDetails(Mesh tMesh)
    {
        foreach (MeshDetails tMeshDetails in ActiveMeshDetails)
        {
            if (tMeshDetails.mesh==tMesh) return tMeshDetails;
        }
        return null;

    }


    void CheckResources()
    {
        ActiveTextures.Clear();
        ActiveMaterials.Clear();
        ActiveMeshDetails.Clear();
        MissingObjects.Clear ();
        thingsMissing = false;

        Renderer[] renderers = FindObjects<Renderer>();

        MaterialDetails skyMat = new MaterialDetails ();
        skyMat.material = RenderSettings.skybox;
        skyMat.isSky = true;
        ActiveMaterials.Add (skyMat);

        //Debug.Log("Total renderers "+renderers.Length);
        foreach (Renderer renderer in renderers)
        {
            //Debug.Log("Renderer is "+renderer.name);
            foreach (Material material in renderer.sharedMaterials)
            {

                MaterialDetails tMaterialDetails = FindMaterialDetails(material);
                if (tMaterialDetails == null)
                {
                    tMaterialDetails = new MaterialDetails();
                    tMaterialDetails.material = material;
                    ActiveMaterials.Add(tMaterialDetails);
                }
                tMaterialDetails.FoundInRenderers.Add(renderer);
            }

            if (renderer is SpriteRenderer)
            {
                SpriteRenderer tSpriteRenderer = (SpriteRenderer)renderer;

                if (tSpriteRenderer.sprite != null) {
                    var tSpriteTextureDetail = GetTextureDetail (tSpriteRenderer.sprite.texture, renderer);
                    if (!ActiveTextures.Contains (tSpriteTextureDetail)) {
                        ActiveTextures.Add (tSpriteTextureDetail);
                    }
                } else if (tSpriteRenderer.sprite == null) {
                    MissingGraphic tMissing = new MissingGraphic ();
                    tMissing.Object = tSpriteRenderer.transform;
                    tMissing.type = "sprite";
                    tMissing.name = tSpriteRenderer.transform.name;
                    MissingObjects.Add (tMissing);
                    thingsMissing = true;
                }
            }
        }

        if (IncludeGuiElements)
        {
            Graphic[] graphics = FindObjects<Graphic>();

            foreach(Graphic graphic in graphics)
            {
                if (graphic.mainTexture)
                {
                    var tSpriteTextureDetail = GetTextureDetail(graphic.mainTexture, graphic);
                    if (!ActiveTextures.Contains(tSpriteTextureDetail))
                    {
                        ActiveTextures.Add(tSpriteTextureDetail);
                    }
                }

                if (graphic.materialForRendering)
                {
                    MaterialDetails tMaterialDetails = FindMaterialDetails(graphic.materialForRendering);
                    if (tMaterialDetails == null)
                    {
                        tMaterialDetails = new MaterialDetails();
                        tMaterialDetails.material = graphic.materialForRendering;
                        tMaterialDetails.isgui = true;
                        ActiveMaterials.Add(tMaterialDetails);
                    }
                    tMaterialDetails.FoundInGraphics.Add(graphic);
                }
            }
        }

        foreach (MaterialDetails tMaterialDetails in ActiveMaterials)
        {
            Material tMaterial = tMaterialDetails.material;
            if (tMaterial != null)
            {
                var dependencies = EditorUtility.CollectDependencies(new UnityEngine.Object[] { tMaterial });
                foreach (Object obj in dependencies)
                {
                    if (obj is Texture)
                    {
                        Texture tTexture = obj as Texture;
                        var tTextureDetail = GetTextureDetail(tTexture, tMaterial, tMaterialDetails);
                        tTextureDetail.isSky = tMaterialDetails.isSky;
                        tTextureDetail.instance = tMaterialDetails.instance;
                        tTextureDetail.isgui = tMaterialDetails.isgui;
                        ActiveTextures.Add(tTextureDetail);
                    }
                }

                //if the texture was downloaded, it won't be included in the editor dependencies
                if (tMaterial.HasProperty ("_MainTex")) {
                    if (tMaterial.mainTexture != null && !dependencies.Contains (tMaterial.mainTexture)) {
                        var tTextureDetail = GetTextureDetail (tMaterial.mainTexture, tMaterial, tMaterialDetails);
                        ActiveTextures.Add (tTextureDetail);
                    }
                }
            }
        }


        MeshFilter[] meshFilters = FindObjects<MeshFilter>();

        foreach (MeshFilter tMeshFilter in meshFilters)
        {
            Mesh tMesh = tMeshFilter.sharedMesh;
            if (tMesh != null)
            {
                MeshDetails tMeshDetails = FindMeshDetails(tMesh);
                if (tMeshDetails == null)
                {
                    tMeshDetails = new MeshDetails();
                    tMeshDetails.mesh = tMesh;
                    ActiveMeshDetails.Add(tMeshDetails);
                }
                tMeshDetails.FoundInMeshFilters.Add(tMeshFilter);
            } else if (tMesh == null && tMeshFilter.transform.GetComponent("TextContainer")== null) {
                MissingGraphic tMissing = new MissingGraphic ();
                tMissing.Object = tMeshFilter.transform;
                tMissing.type = "mesh";
                tMissing.name = tMeshFilter.transform.name;
                MissingObjects.Add (tMissing);
                thingsMissing = true;
            }

            var meshRenderrer = tMeshFilter.transform.GetComponent<MeshRenderer>();
                
            if (meshRenderrer == null || meshRenderrer.sharedMaterial == null) {
                MissingGraphic tMissing = new MissingGraphic ();
                tMissing.Object = tMeshFilter.transform;
                tMissing.type = "material";
                tMissing.name = tMeshFilter.transform.name;
                MissingObjects.Add (tMissing);
                thingsMissing = true;
            }
        }

        SkinnedMeshRenderer[] skinnedMeshRenderers = FindObjects<SkinnedMeshRenderer>();

        foreach (SkinnedMeshRenderer tSkinnedMeshRenderer in skinnedMeshRenderers)
        {
            Mesh tMesh = tSkinnedMeshRenderer.sharedMesh;
            if (tMesh != null)
            {
                MeshDetails tMeshDetails = FindMeshDetails(tMesh);
                if (tMeshDetails == null)
                {
                    tMeshDetails = new MeshDetails();
                    tMeshDetails.mesh = tMesh;
                    ActiveMeshDetails.Add(tMeshDetails);
                }
                tMeshDetails.FoundInSkinnedMeshRenderer.Add(tSkinnedMeshRenderer);
            } else if (tMesh == null) {
                MissingGraphic tMissing = new MissingGraphic ();
                tMissing.Object = tSkinnedMeshRenderer.transform;
                tMissing.type = "mesh";
                tMissing.name = tSkinnedMeshRenderer.transform.name;
                MissingObjects.Add (tMissing);
                thingsMissing = true;
            }
            if (tSkinnedMeshRenderer.sharedMaterial == null) {
                MissingGraphic tMissing = new MissingGraphic ();
                tMissing.Object = tSkinnedMeshRenderer.transform;
                tMissing.type = "material";
                tMissing.name = tSkinnedMeshRenderer.transform.name;
                MissingObjects.Add (tMissing);
                thingsMissing = true;
            }
        }

        if (IncludeSpriteAnimations)
        {
            Animator[] animators = FindObjects<Animator>();
            foreach (Animator anim in animators)
            {
                #if UNITY_4_6 || UNITY_4_5 || UNITY_4_4 || UNITY_4_3
                UnityEditorInternal.AnimatorController ac = anim.runtimeAnimatorController as UnityEditorInternal.AnimatorController;
                #elif UNITY_5 || UNITY_5_3_OR_NEWER
                UnityEditor.Animations.AnimatorController ac = anim.runtimeAnimatorController as UnityEditor.Animations.AnimatorController;
                #endif

                //Skip animators without layers, this can happen if they don't have an animator controller.
                if (!ac || ac.layers == null || ac.layers.Length == 0)
                    continue;

                for (int x = 0; x < anim.layerCount; x++)
                {
                    #if UNITY_4_6 || UNITY_4_5 || UNITY_4_4 || UNITY_4_3
                    UnityEditorInternal.StateMachine sm = ac.GetLayer(x).stateMachine;
                    int cnt = sm.stateCount;
                    #elif UNITY_5 || UNITY_5_3_OR_NEWER
                    UnityEditor.Animations.AnimatorStateMachine sm = ac.layers[x].stateMachine;
                    int cnt = sm.states.Length;
                    #endif

                    for (int i = 0; i < cnt; i++)
                    {
                        #if UNITY_4_6 || UNITY_4_5 || UNITY_4_4 || UNITY_4_3
                        UnityEditorInternal.State state = sm.GetState(i);
                        Motion m = state.GetMotion();
                        #elif UNITY_5 || UNITY_5_3_OR_NEWER
                        UnityEditor.Animations.AnimatorState state = sm.states[i].state;
                        Motion m = state.motion;
                        #endif
                        if (m != null)
                        {
                            AnimationClip clip = m as AnimationClip;

                            if (clip != null)
                            {
                                EditorCurveBinding[] ecbs = AnimationUtility.GetObjectReferenceCurveBindings(clip);

                                foreach (EditorCurveBinding ecb in ecbs)
                                {
                                    if (ecb.propertyName == "m_Sprite")
                                    {
                                        foreach (ObjectReferenceKeyframe keyframe in AnimationUtility.GetObjectReferenceCurve(clip, ecb))
                                        {
                                            Sprite tSprite = keyframe.value as Sprite;

                                            if (tSprite != null)
                                            {
                                                var tTextureDetail = GetTextureDetail(tSprite.texture, anim);
                                                if (!ActiveTextures.Contains(tTextureDetail))
                                                {
                                                    ActiveTextures.Add(tTextureDetail);
                                                }
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                }

            }
        }

        if (IncludeScriptReferences)
        {
            MonoBehaviour[] scripts = FindObjects<MonoBehaviour>();
            foreach (MonoBehaviour script in scripts)
            {
                BindingFlags flags = BindingFlags.Public | BindingFlags.Instance; // only public non-static fields are bound to by Unity.
                FieldInfo[] fields = script.GetType().GetFields(flags);

                foreach (FieldInfo field in fields)
                {
                    System.Type fieldType = field.FieldType;
                    if (fieldType == typeof(Sprite))
                    {
                        Sprite tSprite = field.GetValue(script) as Sprite;
                        if (tSprite != null)
                        {
                            var tSpriteTextureDetail = GetTextureDetail(tSprite.texture, script);
                            if (!ActiveTextures.Contains(tSpriteTextureDetail))
                            {
                                ActiveTextures.Add(tSpriteTextureDetail);
                            }
                        }
                    }if (fieldType == typeof(Mesh))
                    {
                        Mesh tMesh = field.GetValue(script) as Mesh;
                        if (tMesh != null)
                        {
                            MeshDetails tMeshDetails = FindMeshDetails(tMesh);
                            if (tMeshDetails == null)
                            {
                                tMeshDetails = new MeshDetails();
                                tMeshDetails.mesh = tMesh;
                                tMeshDetails.instance = true;
                                ActiveMeshDetails.Add(tMeshDetails);
                            }
                        }
                    }if (fieldType == typeof(Material))
                    {
                        Material tMaterial = field.GetValue(script) as Material;
                        if (tMaterial != null)
                        {
                            MaterialDetails tMatDetails = FindMaterialDetails(tMaterial);
                            if (tMatDetails == null)
                            {
                                tMatDetails = new MaterialDetails();
                                tMatDetails.instance = true;
                                tMatDetails.material = tMaterial;
                                if(!ActiveMaterials.Contains(tMatDetails))
                                    ActiveMaterials.Add(tMatDetails);
                            }
                            if (tMaterial.mainTexture)
                            {
                                var tSpriteTextureDetail = GetTextureDetail(tMaterial.mainTexture);
                                if (!ActiveTextures.Contains(tSpriteTextureDetail))
                                {
                                    ActiveTextures.Add(tSpriteTextureDetail);
                                }
                            }
                            var dependencies = EditorUtility.CollectDependencies(new UnityEngine.Object[] { tMaterial });
                            foreach (Object obj in dependencies)
                            {
                                if (obj is Texture)
                                {
                                    Texture tTexture = obj as Texture;
                                    var tTextureDetail = GetTextureDetail(tTexture, tMaterial, tMatDetails);
                                    if(!ActiveTextures.Contains(tTextureDetail))
                                        ActiveTextures.Add(tTextureDetail);
                                }
                            }
                        }
                    }
                }
            }
        }

        TotalTextureMemory = 0;
        foreach (TextureDetails tTextureDetails in ActiveTextures) TotalTextureMemory += tTextureDetails.memSizeKB;

        TotalMeshVertices = 0;
        foreach (MeshDetails tMeshDetails in ActiveMeshDetails) TotalMeshVertices += tMeshDetails.mesh.vertexCount;

        // Sort by size, descending
        ActiveTextures.Sort(delegate(TextureDetails details1, TextureDetails details2) { return details2.memSizeKB - details1.memSizeKB; });
        ActiveTextures = ActiveTextures.Distinct().ToList();
        ActiveMeshDetails.Sort(delegate(MeshDetails details1, MeshDetails details2) { return details2.mesh.vertexCount - details1.mesh.vertexCount; });

        collectedInPlayingMode = Application.isPlaying;
    }

    private static GameObject[] GetAllRootGameObjects()
    {
#if !UNITY_5 && !UNITY_5_3_OR_NEWER
        return UnityEngine.SceneManagement.SceneManager.GetActiveScene().GetRootGameObjects().ToArray();
#else
        List<GameObject> allGo = new List<GameObject>();
        for (int sceneIdx = 0; sceneIdx < UnityEngine.SceneManagement.SceneManager.sceneCount; ++sceneIdx){
            allGo.AddRange( UnityEngine.SceneManagement.SceneManager.GetSceneAt(sceneIdx).GetRootGameObjects().ToArray() );
        }
        return allGo.ToArray();
#endif
    }

    private T[] FindObjects<T>() where T : Object
    {
        if (IncludeDisabledObjects) {
            List<T> meshfilters = new List<T> ();
            GameObject[] allGo = GetAllRootGameObjects();
            foreach (GameObject go in allGo) {
                Transform[] tgo = go.GetComponentsInChildren<Transform> (true).ToArray ();
                foreach (Transform tr in tgo) {
                    if (tr.GetComponent<T> ())
                        meshfilters.Add (tr.GetComponent<T> ());
                }
            }
            return (T[])meshfilters.ToArray ();
        }
        else
            return (T[])FindObjectsOfType(typeof(T));
    }

    private TextureDetails GetTextureDetail(Texture tTexture, Material tMaterial, MaterialDetails tMaterialDetails)
    {
        TextureDetails tTextureDetails = GetTextureDetail(tTexture);

        tTextureDetails.FoundInMaterials.Add(tMaterial);
        foreach (Renderer renderer in tMaterialDetails.FoundInRenderers)
        {
            if (!tTextureDetails.FoundInRenderers.Contains(renderer)) tTextureDetails.FoundInRenderers.Add(renderer);
        }
        return tTextureDetails;
    }

    private TextureDetails GetTextureDetail(Texture tTexture, Renderer renderer)
    {
        TextureDetails tTextureDetails = GetTextureDetail(tTexture);

        tTextureDetails.FoundInRenderers.Add(renderer);
        return tTextureDetails;
    }

    private TextureDetails GetTextureDetail(Texture tTexture, Animator animator)
    {
        TextureDetails tTextureDetails = GetTextureDetail(tTexture);

        tTextureDetails.FoundInAnimators.Add(animator);
        return tTextureDetails;
    }

    private TextureDetails GetTextureDetail(Texture tTexture, Graphic graphic)
    {
        TextureDetails tTextureDetails = GetTextureDetail(tTexture);

        tTextureDetails.FoundInGraphics.Add(graphic);
        return tTextureDetails;
    }

    private TextureDetails GetTextureDetail(Texture tTexture, MonoBehaviour script)
    {
        TextureDetails tTextureDetails = GetTextureDetail(tTexture);

        tTextureDetails.FoundInScripts.Add(script);
        return tTextureDetails;
    }

    private TextureDetails GetTextureDetail(Texture tTexture)
    {
        TextureDetails tTextureDetails = FindTextureDetails(tTexture);
        if (tTextureDetails == null)
        {
            tTextureDetails = new TextureDetails();
            tTextureDetails.texture = tTexture;
            tTextureDetails.isCubeMap = tTexture is Cubemap;

            int memSize = CalculateTextureSizeBytes(tTexture);

            TextureFormat tFormat = TextureFormat.RGBA32;
            int tMipMapCount = 1;
            if (tTexture is Texture2D)
            {
                tFormat = (tTexture as Texture2D).format;
                tMipMapCount = (tTexture as Texture2D).mipmapCount;
            }
            if (tTexture is Cubemap)
            {
                tFormat = (tTexture as Cubemap).format;
                memSize = 8 * tTexture.height * tTexture.width;
            }
            if(tTexture is Texture2DArray){
                tFormat = (tTexture as Texture2DArray).format;
                tMipMapCount = 10;
            }

            tTextureDetails.memSizeKB = memSize / 1024;
            tTextureDetails.format = tFormat;
            tTextureDetails.mipMapCount = tMipMapCount;

        }

        return tTextureDetails;
    }

}

下载地址：https://github.com/handcircus/Unity-Resource-Checker

使用：Unity导航菜单栏中选择 Windows -> Resource Checker ，点击即可

二、UnityAssetCleaner 

超级diao炸天的插件，强烈推荐使用，有三种清理资源的模式，更重要的是，它把assets下的资源删除后，

自动将删除的文件备份一个package包，这样再也不用担心误删有用的资源啦，误删了，大不了再把package包导进来呗。

代码：

/**
    asset cleaner
    Copyright (c) 2015 Tatsuhiko Yamamura

    This software is released under the MIT License.
    http://opensource.org/licenses/mit-license.php
*/
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using UnityEditor;
using System.IO;
using System.Text.RegularExpressions;

namespace AssetClean
{
    public class AssetCollector
    {
        public List<string> deleteFileList = new List<string> ();
        ClassReferenceCollection classCollection = new ClassReferenceCollection ();
        ShaderReferenceCollection shaderCollection = new ShaderReferenceCollection ();

        public bool useCodeStrip = true;
        public bool saveEditorExtensions = true;

        public void Collection ()
        {
            try {
                deleteFileList.Clear ();

                if( useCodeStrip ){
                    classCollection.Collection ();
                }
                shaderCollection.Collection ();

                // Find assets
                var files = Directory.GetFiles ("Assets", "*.*", SearchOption.AllDirectories)
                    .Where (item => Path.GetExtension (item) != ".meta")
                    .Where (item => Path.GetExtension (item) != ".js")
                    .Where (item => Path.GetExtension (item) != ".dll")
                    .Where (item => Regex.IsMatch (item, "[\/\\]Gizmos[\/\\]") == false)
                    .Where (item => Regex.IsMatch (item, "[\/\\]Plugins[\/\\]Android[\/\\]") == false)
                    .Where (item => Regex.IsMatch (item, "[\/\\]Plugins[\/\\]iOS[\/\\]") == false)
                    .Where (item => Regex.IsMatch (item, "[\/\\]Resources[\/\\]") == false);

                if( useCodeStrip == false ){
                    files = files.Where( item => Path.GetExtension(item) != ".cs");
                }

                foreach (var path in files) {
                    var guid = AssetDatabase.AssetPathToGUID (path);
                    deleteFileList.Add (guid);
                }
                EditorUtility.DisplayProgressBar ("checking", "collection all files", 0.2f);
                UnregistReferenceFromResources();
                
                EditorUtility.DisplayProgressBar ("checking", "check reference from resources", 0.4f);
                UnregistReferenceFromScenes();

                EditorUtility.DisplayProgressBar ("checking", "check reference from scenes", 0.6f);
                if( saveEditorExtensions ){
                    UnregistEditorCodes();
                }
            } finally {
                EditorUtility.ClearProgressBar ();
            }
        }
        void UnregistReferenceFromResources()
        {
            var resourcesFiles = Directory.GetFiles ("Assets", "*.*", SearchOption.AllDirectories)
                .Where (item => Regex.IsMatch (item, "[\/\\]Resources[\/\\]") == true)
                    .Where (item => Path.GetExtension (item) != ".meta")
                    .ToArray ();
            foreach (var path in AssetDatabase.GetDependencies (resourcesFiles)) {
                UnregistFromDelteList (AssetDatabase.AssetPathToGUID(path));
            }
        }
        
        void UnregistReferenceFromScenes()
        {
            // Exclude objects that reference from scenes.
            var scenes = EditorBuildSettings.scenes
                .Where (item => item.enabled == true)
                    .Select (item => item.path)
                    .ToArray ();
            foreach (var path in AssetDatabase.GetDependencies (scenes)) {
                if( saveEditorExtensions == false ){
                    Debug.Log(path);
                }
                UnregistFromDelteList (AssetDatabase.AssetPathToGUID(path));
            } 
        }

        void UnregistEditorCodes()
        {
            // Exclude objects that reference from Editor API
            var editorcodes = Directory.GetFiles ("Assets", "*.cs", SearchOption.AllDirectories)
                .Where (item => Regex.IsMatch (item, "[\/\\]Editor[\/\\]") == true)
                    .ToArray ();
            
            var undeleteClassList = classCollection.codeFileList
                .Where (codefile => codefile.Value.Any( guid => deleteFileList.Contains(guid)) == false)
                    .Select( item => item.Key );
            
            EditorUtility.DisplayProgressBar ("checking", "check reference from editor codes", 0.8f);
            
            foreach (var path in editorcodes) {
                var code = File.ReadAllText (path);
                code = Regex.Replace(code, "//.*[\n\r]", "");
                code = Regex.Replace(code, "/\*.*[\n\r]\*/", "");
                if (Regex.IsMatch (code, "(\[MenuItem|AssetPostprocessor|EditorWindow)")) {
                    UnregistFromDelteList ( AssetDatabase.AssetPathToGUID(path));
                    continue;
                }
                
                foreach (var undeleteClass in undeleteClassList) {
                    if (Regex.IsMatch (code, string.Format ("\[CustomEditor.*\(\s*{0}\s*\).*\]", undeleteClass.Name))) {
                        UnregistFromDelteList (path);
                        continue;
                    }
                }
            }
        }

        void UnregistFromDelteList (string guid)
        {
            if (deleteFileList.Contains (guid) == false) {
                return;
            }
            deleteFileList.Remove (guid);
            
            if (classCollection.references.ContainsKey (guid) == true) {
                
                foreach (var type in classCollection.references[guid]) {
                    var codePaths = classCollection.codeFileList [type];
                    foreach( var codePath in codePaths){
                        UnregistFromDelteList (codePath);
                    }
                }
            }
            
            if (shaderCollection.shaderFileList.ContainsValue (guid)) {
                var shader = shaderCollection.shaderFileList.First (item => item.Value == guid);
                var shaderAssets = shaderCollection.shaderReferenceList [shader.Key];
                foreach (var shaderPath in shaderAssets) {
                    UnregistFromDelteList (shaderPath);
                }
            }
        }
    }
}

/**
    asset cleaner
    Copyright (c) 2015 Tatsuhiko Yamamura

    This software is released under the MIT License.
    http://opensource.org/licenses/mit-license.php
*/
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using UnityEditor;
using System.IO;
using System.Reflection;
using System.Linq;

namespace AssetClean
{
    public class ClassReferenceCollection
    {
        // type : guid
        public Dictionary<System.Type, List<string>> codeFileList = new Dictionary<System.Type, List<string>> ();
        // guid : types
        public Dictionary<string, List<System.Type>> references = new Dictionary<string, List<System.Type>> ();

        public void Collection ()
        {
            references.Clear ();
            EditorUtility.DisplayProgressBar ("checking", "collection all type", 0);

            // Connect the files and class.
            var codes = Directory.GetFiles ("Assets", "*.cs", SearchOption.AllDirectories);
            // connect each classes.
            var firstPassList = new List<string>();
            if( Directory.Exists ("Assets/Plugins") )
                firstPassList.AddRange( Directory.GetFiles ("Assets/Plugins", "*.cs", SearchOption.AllDirectories));
            if( Directory.Exists ("Assets/Standard Assets") )
                firstPassList.AddRange( Directory.GetFiles ("Assets/Standard Assets", "*.cs", SearchOption.AllDirectories));

            var allFirstpassTypes = collectionAllFastspassClasses ();
            CollectionCodeFileDictionary (allFirstpassTypes, firstPassList.ToArray());


            var alltypes = CollectionAllClasses ();
            CollectionCodeFileDictionary (alltypes, codes.ToArray());
            alltypes.AddRange (allFirstpassTypes);

            int count = 0;
            foreach (var codepath in firstPassList) {
                CollectionReferenceClasses (AssetDatabase.AssetPathToGUID (codepath), allFirstpassTypes);
                EditorUtility.DisplayProgressBar ("checking", "analytics codes", ((float)++count / codes.Length) * 0.5f + 0.5f);
            }
            count = 0;
            foreach (var codepath in codes) {
                CollectionReferenceClasses (AssetDatabase.AssetPathToGUID (codepath), alltypes);
                EditorUtility.DisplayProgressBar ("checking", "analytics codes", ((float)++count / codes.Length) * 0.5f);
            }
        }

        void CollectionCodeFileDictionary (List<System.Type> alltypes, string[] codes)
        {
            float count = 1;
            foreach (var codePath in codes) {
                EditorUtility.DisplayProgressBar ("checking", "search files", count++ / codes.Length);

                // connect file and classes.
                var code = System.IO.File.ReadAllText (codePath);
                code = Regex.Replace(code, "//.*[\n\r]", "");
                code = Regex.Replace(code, "/\*.*[\n\r]\*/", "");

                foreach (var type in alltypes) {

                    if( codeFileList.ContainsKey(type ) == false ){
                        codeFileList.Add(type, new List<string>());
                    }
                    var list = codeFileList[type];
                
                    if (string.IsNullOrEmpty (type.Namespace) == false) {
                        var namespacepattern = string.Format ("namespace[\s.]{0}[{{\s\n]", type.Namespace);
                        if (Regex.IsMatch (code, namespacepattern) == false) {
                            continue;
                        }
                    }

                    string typeName = type.IsGenericTypeDefinition ? type.GetGenericTypeDefinition ().Name.Split ('`') [0] : type.Name;
                    if (Regex.IsMatch (code, string.Format ("class\s*{0}?[\s:<{{]", typeName))) {
                        list.Add( AssetDatabase.AssetPathToGUID(codePath) );
                        continue;
                    }

                    if (Regex.IsMatch (code, string.Format ("struct\s*{0}[\s:<{{]", typeName))) {
                        list.Add( AssetDatabase.AssetPathToGUID(codePath) );
                        continue;
                    }
                
                    if (Regex.IsMatch (code, string.Format ("enum\s*{0}[\s{{]", type.Name))) {
                        list.Add( AssetDatabase.AssetPathToGUID(codePath) );
                        continue;
                    }
                
                    if (Regex.IsMatch (code, string.Format ("delegate\s*{0}\s\(", type.Name))) {
                        list.Add( AssetDatabase.AssetPathToGUID(codePath) );
                        continue;
                    }
                }
            }
        }

        List<System.Type> CollectionAllClasses ()
        {
            List<System.Type> alltypes = new List<System.Type> ();
        
            if (File.Exists ("Library/ScriptAssemblies/Assembly-CSharp.dll"))
                alltypes.AddRange (Assembly.LoadFile ("Library/ScriptAssemblies/Assembly-CSharp.dll").GetTypes ());
            if (File.Exists ("Library/ScriptAssemblies/Assembly-CSharp-Editor.dll"))
                alltypes.AddRange (Assembly.LoadFile ("Library/ScriptAssemblies/Assembly-CSharp-Editor.dll").GetTypes ());

            return alltypes    .ToList ();
        }

        List<System.Type> collectionAllFastspassClasses()
        {
            List<System.Type> alltypes = new List<System.Type> ();
            if (File.Exists ("Library/ScriptAssemblies/Assembly-CSharp-firstpass.dll"))
                alltypes.AddRange (Assembly.LoadFile ("Library/ScriptAssemblies/Assembly-CSharp-firstpass.dll").GetTypes ());
            if (File.Exists ("Library/ScriptAssemblies/Assembly-CSharp-Editor-firstpass.dll"))
                alltypes.AddRange (Assembly.LoadFile ("Library/ScriptAssemblies/Assembly-CSharp-Editor-firstpass.dll").GetTypes ());
            return alltypes;
        }
        
        void CollectionReferenceClasses (string guid, List<System.Type> types)
        {
            var codePath = AssetDatabase.GUIDToAssetPath(guid);
            if (string.IsNullOrEmpty (codePath) || references.ContainsKey (guid) || File.Exists(codePath)==false) {
                return;
            }

            var code = System.IO.File.ReadAllText (codePath);
            code = Regex.Replace(code, "//.*[\n\r]", "");
            code = Regex.Replace(code, "/\*.*[\n\r]\*/", "");

            var list = new List<System.Type> ();
            references [guid] = list;

            foreach (var type in types) {
    
                if (string.IsNullOrEmpty (type.Namespace) == false) {
                    var namespacepattern = string.Format ("[namespace|using][\s\.]{0}[{{\s\r\n\r;]", type.Namespace);
                    if (Regex.IsMatch (code, namespacepattern) == false) {
                        continue;
                    }
                }

                if (codeFileList.ContainsKey (type) == false) {
                    continue;
                }

                string match = string.Empty;
                if (type.IsGenericTypeDefinition) {
                    string typeName = type.GetGenericTypeDefinition ().Name.Split ('`') [0];
                    match = string.Format ("[\]\[\.\s<(]{0}[\.\s\n\r>,<(){{]", typeName);
                } else {
                    match = string.Format ("[\]\[\.\s<(]{0}[\.\s\n\r>,<(){{\]]", type.Name.Replace("Attribute", ""));
                }
                if (Regex.IsMatch (code, match)) {
                    list.Add (type);
                    var typeGuid =  codeFileList[type];
                    foreach( var referenceGuid in typeGuid){
                        CollectionReferenceClasses (referenceGuid, types);
                    }
                }
            }
        }
    }
}

/**
    asset cleaner
    Copyright (c) 2015 Tatsuhiko Yamamura

    This software is released under the MIT License.
    http://opensource.org/licenses/mit-license.php
*/
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using UnityEditor;
using System.IO;
using System.Linq;

namespace AssetClean
{
    public class FindUnusedAssets : EditorWindow
    {
        AssetCollector collection = new AssetCollector ();
        List<DeleteAsset> deleteAssets = new List<DeleteAsset> ();
        Vector2 scroll;

        [MenuItem("Assets/Delete Unused Assets/only resource", false, 50)]
        static void InitWithoutCode ()
        {
            var window = FindUnusedAssets.CreateInstance<FindUnusedAssets> ();
            window.collection.useCodeStrip = false;
            window.collection.Collection ();
            window.CopyDeleteFileList (window.collection.deleteFileList);
            
            window.Show ();
        }

        [MenuItem("Assets/Delete Unused Assets/unused by editor", false, 51)]
        static void InitWithout ()
        {
            var window = FindUnusedAssets.CreateInstance<FindUnusedAssets> ();
            window.collection.Collection ();
            window.CopyDeleteFileList (window.collection.deleteFileList);
            
            window.Show ();
        }

        [MenuItem("Assets/Delete Unused Assets/unused by game", false, 52)]
        static void Init ()
        {
            var window = FindUnusedAssets.CreateInstance<FindUnusedAssets> ();
            window.collection.saveEditorExtensions = false;
            window.collection.Collection ();
            window.CopyDeleteFileList (window.collection.deleteFileList);
            
            window.Show ();
        }
        
        void OnGUI ()
        {
            using (var horizonal = new EditorGUILayout.HorizontalScope("box")) {
                EditorGUILayout.LabelField ("delete unreference assets from buildsettings and resources");

                if (GUILayout.Button ("Delete", GUILayout.Width (120), GUILayout.Height (40)) && deleteAssets.Count != 0) {
                    RemoveFiles ();
                    Close ();
                }
            }

            using (var scrollScope = new EditorGUILayout.ScrollViewScope(scroll)) {
                scroll = scrollScope.scrollPosition;
                foreach (var asset in deleteAssets) {
                    if (string.IsNullOrEmpty (asset.path)) {
                        continue;
                    }

                    using (var horizonal = new EditorGUILayout.HorizontalScope()) {
                        asset.isDelete = EditorGUILayout.Toggle (asset.isDelete, GUILayout.Width (20));
                        var icon = AssetDatabase.GetCachedIcon (asset.path);
                        GUILayout.Label (icon, GUILayout.Width (20), GUILayout.Height (20));
                        if (GUILayout.Button (asset.path, EditorStyles.largeLabel)) {
                            Selection.activeObject = AssetDatabase.LoadAssetAtPath<Object> (asset.path);
                        }
                    }
                }
            }

        }

         static void CleanDir()
         {
            RemoveEmptyDirectry ("Assets");
            AssetDatabase.Refresh ();
        }

        void CopyDeleteFileList(IEnumerable<string> deleteFileList)
        {
            foreach (var asset in deleteFileList) {
                var filePath = AssetDatabase.GUIDToAssetPath (asset);
                if (string.IsNullOrEmpty (filePath) == false) {
                    deleteAssets.Add (new DeleteAsset (){ path = filePath});
                }
            }
        }

        void RemoveFiles ()
        {
            try {
                string exportDirectry = "BackupUnusedAssets";
                Directory.CreateDirectory (exportDirectry);
                var files = deleteAssets.Where (item => item.isDelete == true).Select (item => item.path).ToArray ();
                string backupPackageName = exportDirectry + "/package" + System.DateTime.Now.ToString ("yyyyMMddHHmmss") + ".unitypackage";
                EditorUtility.DisplayProgressBar ("export package", backupPackageName, 0);
                AssetDatabase.ExportPackage (files, backupPackageName);

                int i = 0;
                int length = deleteAssets.Count;

                foreach (var assetPath in files) {
                    i++;
                    EditorUtility.DisplayProgressBar ("delete unused assets", assetPath, (float)i / length);
                    AssetDatabase.DeleteAsset (assetPath);
                }

                EditorUtility.DisplayProgressBar ("clean directory", "", 1);
                foreach (var dir in Directory.GetDirectories("Assets")) {
                    RemoveEmptyDirectry (dir);
                }

                System.Diagnostics.Process.Start (exportDirectry);

                AssetDatabase.Refresh ();
            }
            catch( System.Exception e ){
                Debug.Log(e.Message);
            }finally {
                EditorUtility.ClearProgressBar ();
            }
        }

        static void RemoveEmptyDirectry (string path)
        {
            var dirs = Directory.GetDirectories (path);
            foreach (var dir in dirs) {
                RemoveEmptyDirectry (dir);
            }

            var files = Directory.GetFiles (path, "*", SearchOption.TopDirectoryOnly).Where (item => Path.GetExtension (item) != ".meta");
            if (files.Count () == 0 && Directory.GetDirectories (path).Count () == 0) {
                var metaFile = AssetDatabase.GetTextMetaFilePathFromAssetPath(path);
                UnityEditor.FileUtil.DeleteFileOrDirectory (path);
                UnityEditor.FileUtil.DeleteFileOrDirectory (metaFile);
            }
        }

        class DeleteAsset
        {
            public bool isDelete = true;
            public string path;
        }
    }
}

/**
    asset cleaner
    Copyright (c) 2015 Tatsuhiko Yamamura

    This software is released under the MIT License.
    http://opensource.org/licenses/mit-license.php
*/
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Text.RegularExpressions;
using UnityEditor;

namespace AssetClean
{
    public class ShaderReferenceCollection
    {
        // shader name / shader file guid
        public Dictionary<string, string> shaderFileList = new Dictionary<string, string> ();
        public Dictionary<string, List<string> > shaderReferenceList = new Dictionary<string, List<string>> ();

        public void Collection ()
        {
            CollectionShaderFiles ();
            CheckReference ();
        }

        void CollectionShaderFiles ()
        {
            var shaderFiles = Directory.GetFiles ("Assets", "*.shader", SearchOption.AllDirectories);
            foreach (var shaderFilePath in shaderFiles) {
                var code = File.ReadAllText (shaderFilePath);
                var match = Regex.Match (code, "Shader "(?<name>.*)"");
                if (match.Success) {
                    var shaderName = match.Groups ["name"].ToString ();
                    if (shaderFileList.ContainsKey (shaderName) == false) {
                        shaderFileList.Add (shaderName, AssetDatabase.AssetPathToGUID(shaderFilePath));
                    }
                }
            }
        
            var cgFiles = Directory.GetFiles ("Assets", "*.cg", SearchOption.AllDirectories);
            foreach (var cgFilePath in cgFiles) {
                var file = Path.GetFileName (cgFilePath);
                shaderFileList.Add (file, cgFilePath);
            }

            var cgincFiles = Directory.GetFiles ("Assets", "*.cginc", SearchOption.AllDirectories);
            foreach (var cgincPath in cgincFiles) {
                var file = Path.GetFileName (cgincPath);
                shaderFileList.Add (file, cgincPath);
            }
        }

        void CheckReference ()
        {
            foreach (var shader in shaderFileList) {
                var shaderFilePath = AssetDatabase.GUIDToAssetPath(shader.Value);
                var shaderName = shader.Key;
            
                List<string> referenceList = new List<string> ();
                shaderReferenceList.Add (shaderName, referenceList);
            
                var code = File.ReadAllText (shaderFilePath);
            
                foreach (var checkingShaderName in shaderFileList.Keys) {
                    if (Regex.IsMatch (code, string.Format ("{0}", checkingShaderName))) {
                        var filePath = shaderFileList [checkingShaderName];
                        referenceList.Add (filePath);
                    }
                }
            }
        }
    }
}

下载地址：https://github.com/unity-cn/Tool-UnityAssetCleaner

使用：Unity导航菜单栏中选择 Assets-> Delete Unused Assets

三种模式，选择一个合适的，然后点击Delete，轻松搞定