feat: Add Bioxel asset catalog and layer management functionality

- Introduced a new asset catalog definition file for Blender to manage Bioxel assets.
- Implemented layer caching and snapshot functionality in `layer.py`, allowing for VDB file generation and low-resolution snapshots.
- Created node management functions in `node.py` for handling Bioxel nodes within Blender's Geometry Node Editor.
- Added an operator to extract mesh data from selected nodes in `structure.py`.
- Developed UI panels in `panels.py` for layer management, including import options and layer library display.

src/bioxelnodes/__init__.py

@@ -1,26 +1,109 @@
 import bpy
+import bpy.utils.previews as previews
+
+from .constants import NODE_LIB_DIRPATH, PREVIEW_COLLECTIONS
+from .props import _bioxel_layer_items, _update_layer_gallery, _update_snapshot_z
 
-from .props import BIOXELNODES_LayerListUL
 from . import auto_load
 from . import menus
 
-
 auto_load.init()
 
 
+def add_asset_library_if_missing():
+    """检查并添加Asset Library（如果不存在），使用link导入方式"""
+    # 检查路径是否存在
+    if not NODE_LIB_DIRPATH.exists():
+        print(f"警告: 节点库路径不存在 - {NODE_LIB_DIRPATH}")
+        return
+
+    # 转换为字符串路径用于Blender设置
+    lib_path_str = str(NODE_LIB_DIRPATH)
+
+    # 检查是否已存在该资产库
+    prefs = bpy.context.preferences.filepaths.asset_libraries
+    for lib in prefs:
+        if lib.path == lib_path_str:
+            return  # 已存在，无需添加
+
+    # 添加新的资产库，使用link导入方式
+    new_lib = prefs.new()
+    new_lib.name = "O Bioxel"  # 资产库名称
+    new_lib.path = lib_path_str  # 资产库路径（字符串形式）
+    new_lib.import_method = "PACK"  # 设置导入方式为link
+
+    print(f"Add Bioxel Nodes library: {lib_path_str}")
+
+
+def remove_asset_library_if_exists():
+    """Remove the Bioxel asset library entry if it was added (by path or name)."""
+    # if path missing, nothing to remove
+    lib_path_str = str(NODE_LIB_DIRPATH)
+    prefs = bpy.context.preferences.filepaths.asset_libraries
+
+    # iterate over a snapshot of prefs to safely find index
+    lib_to_remove = None
+    for i, lib in enumerate(list(prefs)):
+        try:
+            if lib.path == lib_path_str:
+                lib_to_remove = lib
+                break
+        except Exception:
+            continue
+
+    if lib_to_remove is not None:
+        try:
+            prefs.remove(lib_to_remove)
+            print(f"Removed Bioxel Nodes library: {lib_path_str}")
+        except Exception as e:
+            print(f"Warning: failed to remove Bioxel node library: {e}")
+
+
 def register():
+    pcoll = previews.new()
+    pcoll.layer_previews = ()
+    PREVIEW_COLLECTIONS["layers"] = pcoll
+
+    bpy.types.WindowManager.bioxel_progress_factor = bpy.props.FloatProperty(
+        default=1.0
+    )
+
+    bpy.types.WindowManager.bioxel_progress_text = bpy.props.StringProperty()
+
+    bpy.types.WindowManager.bioxel_layer_library = bpy.props.EnumProperty(
+        name="Bioxel Layer Gallery",
+        items=_bioxel_layer_items,
+        update=_update_layer_gallery,
+    )
+
+    bpy.types.WindowManager.bioxel_snapshot_z = bpy.props.FloatProperty(
+        name="Snapshot Z",
+        default=0.5,
+        min=0.0,
+        max=1.0,
+        subtype="FACTOR",
+        update=_update_snapshot_z,
+    )
+
+    bpy.types.WindowManager.bioxel_layer_list_index = bpy.props.IntProperty(
+        default=0)
+
     auto_load.register()
-    bpy.types.WindowManager.bioxelnodes_progress_factor = bpy.props.FloatProperty(
-        default=1.0)
-    bpy.types.WindowManager.bioxelnodes_progress_text = bpy.props.StringProperty()
-    bpy.types.WindowManager.bioxelnodes_layer_list_UL = bpy.props.PointerProperty(
-        type=BIOXELNODES_LayerListUL)
     menus.add()
+    add_asset_library_if_missing()
 
 
 def unregister():
+    remove_asset_library_if_exists()
     menus.remove()
-    del bpy.types.WindowManager.bioxelnodes_progress_factor
-    del bpy.types.WindowManager.bioxelnodes_progress_text
-    del bpy.types.WindowManager.bioxelnodes_layer_list_UL
     auto_load.unregister()
+
+    del bpy.types.WindowManager.bioxel_progress_factor
+    del bpy.types.WindowManager.bioxel_progress_text
+    del bpy.types.WindowManager.bioxel_layer_library
+    del bpy.types.WindowManager.bioxel_snapshot_z
+    del bpy.types.WindowManager.bioxel_layer_list_index
+
+    for pcoll in PREVIEW_COLLECTIONS.values():
+        previews.remove(pcoll)
+    PREVIEW_COLLECTIONS.clear()