「SpriteProcessorScript」で「Retrieving array element that was out of bounds」というエラーがでる

Question

前提

バージョン : Unity 2020.3.32f1

発生している問題・エラーメッセージ

https://github.com/dithyrambs/SpriteProcessorScript
のSpriteProcessorを利用して、スプライトを Multiple にして自動でスライスできるようにしようと思ったところ、以下のようなエラーが出てしまいました。

Retrieving array element that was out of bounds
UnityEditor.AssetPostprocessingInternal:PostprocessSprites (UnityEngine.Texture2D,string,UnityEngine.Sprite[])

NullReferenceException: Object reference not set to an instance of an object
UnityEditor.U2D.Sprites.SpriteBoneDataTransfer.Load (UnityEditor.SerializedObject importer, UnityEditor.SpriteImportMode mode, System.Int32 index) (at Library/PackageCache/com.unity.2d.sprite@1.0.0/Editor/SpriteEditorModule/TextureImporterDataProviderImplementation.cs:37)
UnityEditor.U2D.Sprites.SpriteBoneDataTransfer.GetBones (UnityEditor.GUID guid) (at Library/PackageCache/com.unity.2d.sprite@1.0.0/Editor/SpriteEditorModule/TextureImporterDataProviderImplementation.cs:27)
UnityEditor.U2D.Animation.SpritePostProcess.PostProcessBoneData (UnityEditor.U2D.Sprites.ISpriteEditorDataProvider spriteDataProvider, System.Single definitionScale, UnityEngine.Sprite[] sprites) (at Library/PackageCache/com.unity.2d.animation@5.1.1/Editor/SpritePostProcess.cs:107)
UnityEditor.U2D.Animation.SpritePostProcess.OnPostprocessSprites (UnityEngine.Texture2D texture, UnityEngine.Sprite[] sprites) (at Library/PackageCache/com.unity.2d.animation@5.1.1/Editor/SpritePostProcess.cs:29)
System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <695d1cc93cca45069c528c15c9fdd749>:0)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <695d1cc93cca45069c528c15c9fdd749>:0)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) (at <695d1cc93cca45069c528c15c9fdd749>:0)
UnityEditor.AssetPostprocessingInternal.InvokeMethodIfAvailable (System.Object target, System.String methodName, System.Object[] args) (at <294703faec74477f8b275446429fba82>:0)
UnityEditor.AssetPostprocessingInternal.CallPostProcessMethods (System.String methodName, System.Object[] args) (at <294703faec74477f8b275446429fba82>:0)
UnityEditor.AssetPostprocessingInternal.PostprocessSprites (UnityEngine.Texture2D tex, System.String pathName, UnityEngine.Sprite[] sprites) (at <294703faec74477f8b275446429fba82>:0)

該当のソースコード

using System.Collections.Generic;
using System.IO;
using UnityEngine;
using UnityEditor;

/// <summary>
/// Note: Will only work when manually triggering "Reimport" on a file, not when importing a file to Unity for the first time.
/// In order for this to work the grandparent directory must be names "AutoProcessedSpriteSheets"
/// The immediate parent directory must be named the desired horizontal tile size of the sliced spritesheet in pixels, plus underscore...
/// plus the desired horizontal tile size of the sliced spritesheet in pixels, plus underscore...
/// plus the desired pixels per unit
///     eg. "16__12_100"
/// </summary>
public class SpriteProcessor : AssetPostprocessor
{
    bool continueProcess = false;
    int ppu = 16;
    int spriteSizeX = 16;
    int spriteSizeY = 16;

    void OnPreprocessTexture()
    {
        if (Directory.GetParent(assetPath).Parent.Name != "AutoProcessedSpriteSheets") return;

        TextureImporter ti = (TextureImporter)assetImporter;
        ti.textureType = TextureImporterType.Sprite;
        ti.spriteImportMode = SpriteImportMode.Multiple;
        ti.mipmapEnabled = false;
        ti.filterMode = FilterMode.Point;
        ti.textureCompression = TextureImporterCompression.Uncompressed;

        string[] parentDir = Directory.GetParent(assetPath).Name.Split('_');

        //If we can't parse the parent directory values as integers, don't continue processing the sprite
        if ( System.Int32.TryParse(parentDir[0], out spriteSizeX) && System.Int32.TryParse(parentDir[1], out spriteSizeY) && System.Int32.TryParse(parentDir[2], out ppu) )
        {
            ti.spritePixelsPerUnit = ppu;
            continueProcess = true;
        }
    }

    public void OnPostprocessTexture(Texture2D texture)
    {
        //If we failed requirement during the PreProcess stage, return
        Debug.LogWarning("******");
        if (!continueProcess) return;
        Debug.LogWarning("***returnされなかったため、メインの処理に入ります***");


        if ( spriteSizeX > 0 && spriteSizeY > 0)
        {
            int colCount = texture.width / spriteSizeX;
            int rowCount = texture.height / spriteSizeY;
            string fileName = System.IO.Path.GetFileNameWithoutExtension(assetPath);
            int i = 0;


            List<SpriteMetaData> metas = new List<SpriteMetaData>();


            for (int r = rowCount - 1; r > -1; r--)
            {
                for (int c = 0; c < colCount; c++)
                {

                    SpriteMetaData meta = new SpriteMetaData();
                    meta.rect = new Rect(c * spriteSizeX, r * spriteSizeY, spriteSizeX, spriteSizeY);
                    meta.name = fileName + "_" + i;
                    metas.Add(meta);
                    i++;
                }
            }

            TextureImporter textureImporter = (TextureImporter)assetImporter;
            textureImporter.spritesheet = metas.ToArray();

        }
    }
    
}

質問

OnPostprocessTetureの中には配列がないように思うのですが、どこでエラーが出ているのでしょうか。

回答よろしくお願いします。

Answer 1

どうやら2D Animationがインストールされていると発生するようですね。エラーメッセージは出るもののスプライトの縦横分割自体はできているように見えましたので、お気になさらない...というのでも実害はないかもしれません。

あれを回避するとなると、プリプロセスの段階でスプライトの分割を行ってしまえばいいのではないか...と思って下記のような形を考えてみましたが、いろんなテクスチャで試したわけではないので不具合を見落としているかもしれません。

using System;
using System.Collections.Generic;
using System.IO;
using System.Reflection;
using UnityEngine;
using UnityEditor;

/// <summary>
/// In order for this to work the grandparent directory must be names "AutoProcessedSpriteSheets"
/// The immediate parent directory must be named the desired horizontal tile size of the sliced spritesheet in pixels, plus underscore...
/// plus the desired vertical tile size of the sliced spritesheet in pixels, plus underscore...
/// plus the desired pixels per unit
///     eg. "16_12_100"
/// </summary>
public class SpriteProcessor : AssetPostprocessor
{
    int ppu = 16;
    int spriteSizeX = 16;
    int spriteSizeY = 16;

    delegate void GetWidthAndHeightDelegate(TextureImporter importer, ref int width, ref int height);

    GetWidthAndHeightDelegate getWidthAndHeight;

    GetWidthAndHeightDelegate GetWidthAndHeight =>
        getWidthAndHeight ??= (GetWidthAndHeightDelegate)Delegate.CreateDelegate(
            typeof(GetWidthAndHeightDelegate),
            typeof(TextureImporter).GetMethod(
                "GetWidthAndHeight",
                BindingFlags.DeclaredOnly | BindingFlags.Instance | BindingFlags.NonPublic));

    void OnPreprocessTexture()
    {
        if (Directory.GetParent(assetPath).Parent.Name != "AutoProcessedSpriteSheets") return;

        TextureImporter ti = (TextureImporter)assetImporter;
        ti.textureType = TextureImporterType.Sprite;
        ti.spriteImportMode = SpriteImportMode.Multiple;
        ti.mipmapEnabled = false;
        ti.filterMode = FilterMode.Point;
        ti.textureCompression = TextureImporterCompression.Uncompressed;

        string[] parentDir = Directory.GetParent(assetPath).Name.Split('_');

        //If we can't parse the parent directory values as integers, don't continue processing the sprite
        if (int.TryParse(parentDir[0], out spriteSizeX) && int.TryParse(parentDir[1], out spriteSizeY) && int.TryParse(parentDir[2], out ppu))
        {
            ti.spritePixelsPerUnit = ppu;
            if (spriteSizeX > 0 && spriteSizeY > 0)
            {
                int textureWidth = 0;
                int textureHeight = 0;
                GetWidthAndHeight(ti, ref textureWidth, ref textureHeight);
                int colCount = textureWidth / spriteSizeX;
                int rowCount = textureHeight / spriteSizeY;
                string fileName = Path.GetFileNameWithoutExtension(assetPath);
                int i = 0;

                List<SpriteMetaData> metas = new List<SpriteMetaData>();

                for (int r = rowCount - 1; r > -1; r--)
                {
                    for (int c = 0; c < colCount; c++)
                    {
                        SpriteMetaData meta = new SpriteMetaData();
                        meta.rect = new Rect(c * spriteSizeX, r * spriteSizeY, spriteSizeX, spriteSizeY);
                        meta.name = fileName + "_" + i;
                        metas.Add(meta);
                        i++;
                    }
                }

                ti.spritesheet = metas.ToArray();
            }
        }
    }
}

Comments

[kurokko]

回答ありがとうございます！
無事、エラーなく分割できるようになりました。
全ての処理をOnPreprocessTextureに書くことによって、スプライトを最初に読み込んだ時にも分割が行われるようになったんですね。

これでゲーム開発が捗ります。
ありがとうございます。