override public void OnInspectorGUI()
        {
            if (serializedObject.isEditingMultipleObjects)
            {
                DrawDefaultInspector();
                return;
            }

            serializedObject.Update();
            atlasAsset = atlasAsset ?? (SpineAtlasAsset)target;
            EditorGUI.BeginChangeCheck();
            EditorGUILayout.PropertyField(atlasFile);
            EditorGUILayout.PropertyField(materials, true);
            if (EditorGUI.EndChangeCheck())
            {
                serializedObject.ApplyModifiedProperties();
                atlasAsset.Clear();
                atlasAsset.GetAtlas();
            }

            if (materials.arraySize == 0)
            {
                EditorGUILayout.HelpBox("No materials", MessageType.Error);
                return;
            }

            for (int i = 0; i < materials.arraySize; i++)
            {
                SerializedProperty prop = materials.GetArrayElementAtIndex(i);
                var material            = (Material)prop.objectReferenceValue;
                if (material == null)
                {
                    EditorGUILayout.HelpBox("Materials cannot be null.", MessageType.Error);
                    return;
                }
            }

            EditorGUILayout.Space();
            if (SpineInspectorUtility.LargeCenteredButton(SpineInspectorUtility.TempContent("Set Mipmap Bias to " + SpineEditorUtilities.Preferences.DEFAULT_MIPMAPBIAS, tooltip: "This may help textures with mipmaps be less blurry when used for 2D sprites.")))
            {
                foreach (var m in atlasAsset.materials)
                {
                    var texture = m.mainTexture;
                    texture.mipMapBias = SpineEditorUtilities.Preferences.DEFAULT_MIPMAPBIAS;
                }
                Debug.Log("Texture mipmap bias set to " + SpineEditorUtilities.Preferences.DEFAULT_MIPMAPBIAS);
            }

            EditorGUILayout.Space();
            if (atlasFile.objectReferenceValue != null)
            {
                if (SpineInspectorUtility.LargeCenteredButton(SpriteSlicesLabel))
                {
                    var atlas = atlasAsset.GetAtlas();
                    foreach (var m in atlasAsset.materials)
                    {
                        UpdateSpriteSlices(m.mainTexture, atlas);
                    }
                }
            }

            EditorGUILayout.Space();

                        #if REGION_BAKING_MESH
            if (atlasFile.objectReferenceValue != null)
            {
                Atlas              atlas   = asset.GetAtlas();
                FieldInfo          field   = typeof(Atlas).GetField("regions", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.NonPublic);
                List <AtlasRegion> regions = (List <AtlasRegion>)field.GetValue(atlas);
                EditorGUILayout.LabelField(new GUIContent("Region Baking", SpineEditorUtilities.Icons.unityIcon));
                EditorGUI.indentLevel++;
                AtlasPage lastPage = null;
                for (int i = 0; i < regions.Count; i++)
                {
                    if (lastPage != regions[i].page)
                    {
                        if (lastPage != null)
                        {
                            EditorGUILayout.Separator();
                            EditorGUILayout.Separator();
                        }
                        lastPage = regions[i].page;
                        Material mat = ((Material)lastPage.rendererObject);
                        if (mat != null)
                        {
                            GUILayout.BeginHorizontal();
                            {
                                EditorGUI.BeginDisabledGroup(true);
                                EditorGUILayout.ObjectField(mat, typeof(Material), false, GUILayout.Width(250));
                                EditorGUI.EndDisabledGroup();
                            }
                            GUILayout.EndHorizontal();
                        }
                        else
                        {
                            EditorGUILayout.LabelField(new GUIContent("Page missing material!", SpineEditorUtilities.Icons.warning));
                        }
                    }
                    GUILayout.BeginHorizontal();
                    {
                        //EditorGUILayout.ToggleLeft(baked[i] ? "" : regions[i].name, baked[i]);
                        bool result = baked[i] ? EditorGUILayout.ToggleLeft("", baked[i], GUILayout.Width(24)) : EditorGUILayout.ToggleLeft("    " + regions[i].name, baked[i]);
                        if (baked[i])
                        {
                            EditorGUILayout.ObjectField(bakedObjects[i], typeof(GameObject), false, GUILayout.Width(250));
                        }
                        if (result && !baked[i])
                        {
                            //bake
                            baked[i]        = true;
                            bakedObjects[i] = SpineEditorUtilities.BakeRegion(atlasAsset, regions[i]);
                            EditorGUIUtility.PingObject(bakedObjects[i]);
                        }
                        else if (!result && baked[i])
                        {
                            //unbake
                            bool unbakeResult = EditorUtility.DisplayDialog("Delete Baked Region", "Do you want to delete the prefab for " + regions[i].name, "Yes", "Cancel");
                            switch (unbakeResult)
                            {
                            case true:
                                //delete
                                string atlasAssetPath    = AssetDatabase.GetAssetPath(atlasAsset);
                                string atlasAssetDirPath = Path.GetDirectoryName(atlasAssetPath);
                                string bakedDirPath      = Path.Combine(atlasAssetDirPath, atlasAsset.name);
                                string bakedPrefabPath   = Path.Combine(bakedDirPath, SpineEditorUtilities.GetPathSafeRegionName(regions[i]) + ".prefab").Replace("\\", "/");
                                AssetDatabase.DeleteAsset(bakedPrefabPath);
                                baked[i] = false;
                                break;

                            case false:
                                //do nothing
                                break;
                            }
                        }
                    }
                    GUILayout.EndHorizontal();
                }
                EditorGUI.indentLevel--;

                                #if BAKE_ALL_BUTTON
                // Check state
                bool allBaked   = true;
                bool allUnbaked = true;
                for (int i = 0; i < regions.Count; i++)
                {
                    allBaked   &= baked[i];
                    allUnbaked &= !baked[i];
                }

                if (!allBaked && GUILayout.Button("Bake All"))
                {
                    for (int i = 0; i < regions.Count; i++)
                    {
                        if (!baked[i])
                        {
                            baked[i]        = true;
                            bakedObjects[i] = SpineEditorUtilities.BakeRegion(atlasAsset, regions[i]);
                        }
                    }
                }
                else if (!allUnbaked && GUILayout.Button("Unbake All"))
                {
                    bool unbakeResult = EditorUtility.DisplayDialog("Delete All Baked Regions", "Are you sure you want to unbake all region prefabs? This cannot be undone.", "Yes", "Cancel");
                    switch (unbakeResult)
                    {
                    case true:
                        //delete
                        for (int i = 0; i < regions.Count; i++)
                        {
                            if (baked[i])
                            {
                                string atlasAssetPath    = AssetDatabase.GetAssetPath(atlasAsset);
                                string atlasAssetDirPath = Path.GetDirectoryName(atlasAssetPath);
                                string bakedDirPath      = Path.Combine(atlasAssetDirPath, atlasAsset.name);
                                string bakedPrefabPath   = Path.Combine(bakedDirPath, SpineEditorUtilities.GetPathSafeRegionName(regions[i]) + ".prefab").Replace("\\", "/");
                                AssetDatabase.DeleteAsset(bakedPrefabPath);
                                baked[i] = false;
                            }
                        }
                        break;

                    case false:
                        //do nothing
                        break;
                    }
                }
                                #endif
            }
                        #else
            if (atlasFile.objectReferenceValue != null)
            {
                int baseIndent = EditorGUI.indentLevel;

                var regions      = SpineAtlasAssetInspector.GetRegions(atlasAsset.GetAtlas());
                int regionsCount = regions.Count;
                using (new EditorGUILayout.HorizontalScope()) {
                    EditorGUILayout.LabelField("Atlas Regions", EditorStyles.boldLabel);
                    EditorGUILayout.LabelField(string.Format("{0} regions total", regionsCount));
                }
                AtlasPage lastPage = null;
                for (int i = 0; i < regionsCount; i++)
                {
                    if (lastPage != regions[i].page)
                    {
                        if (lastPage != null)
                        {
                            EditorGUILayout.Separator();
                            EditorGUILayout.Separator();
                        }
                        lastPage = regions[i].page;
                        Material mat = ((Material)lastPage.rendererObject);
                        if (mat != null)
                        {
                            EditorGUI.indentLevel = baseIndent;
                            using (new GUILayout.HorizontalScope())
                                using (new EditorGUI.DisabledGroupScope(true))
                                    EditorGUILayout.ObjectField(mat, typeof(Material), false, GUILayout.Width(250));
                            EditorGUI.indentLevel = baseIndent + 1;
                        }
                        else
                        {
                            EditorGUILayout.HelpBox("Page missing material!", MessageType.Warning);
                        }
                    }

                    string    regionName = regions[i].name;
                    Texture2D icon       = SpineEditorUtilities.Icons.image;
                    if (regionName.EndsWith(" "))
                    {
                        regionName = string.Format("'{0}'", regions[i].name);
                        icon       = SpineEditorUtilities.Icons.warning;
                        EditorGUILayout.LabelField(SpineInspectorUtility.TempContent(regionName, icon, "Region name ends with whitespace. This may cause errors. Please check your source image filenames."));
                    }
                    else
                    {
                        EditorGUILayout.LabelField(SpineInspectorUtility.TempContent(regionName, icon));
                    }
                }
                EditorGUI.indentLevel = baseIndent;
            }
                        #endif

            if (serializedObject.ApplyModifiedProperties() || SpineInspectorUtility.UndoRedoPerformed(Event.current))
            {
                atlasAsset.Clear();
            }
        }