chore: blender 4.2 blend_method migration warnings

src/io_scene_vrm/common/ops/vrm.py

@@ -139,6 +139,18 @@ def model_draw(
     )
 
 
+def show_material_blender_4_2_warning(
+    execution_context: str = "EXEC_DEFAULT",
+    /,
+    *,
+    material_name_lines: str = "",
+) -> set[str]:
+    return bpy.ops.vrm.show_material_blender_4_2_warning(  # type: ignore[attr-defined, no-any-return]
+        execution_context,
+        material_name_lines=material_name_lines,
+    )
+
+
 def refresh_mtoon1_outline(
     execution_context: str = "EXEC_DEFAULT",
     /,

src/io_scene_vrm/editor/mtoon1/migration.py

@@ -1,6 +1,7 @@
 import functools
 from typing import Final, Optional
 
+import bpy
 from bpy.types import (
     Context,
     Image,
@@ -11,7 +12,7 @@
 )
 from idprop.types import IDPropertyGroup
 
-from ...common import convert, shader
+from ...common import convert, ops, shader, version
 from ...common.gl import GL_LINEAR, GL_NEAREST
 from ...common.logging import get_logger
 from ..extension import get_material_extension
@@ -37,14 +38,45 @@
 logger = get_logger(__name__)
 
 
+def show_material_blender_4_2_warning_delay(material_name_lines: str) -> None:
+    ops.vrm.show_material_blender_4_2_warning(
+        "INVOKE_DEFAULT",
+        material_name_lines=material_name_lines,
+    )
+
+
 def migrate(context: Context) -> None:
+    blender_4_2_migrated_material_names: list[str] = []
     for material in context.blend_data.materials:
         if not material:
             continue
-        migrate_material(context, material)
+        migrate_material(context, material, blender_4_2_migrated_material_names)
+    if (
+        blender_4_2_migrated_material_names
+        and tuple(bpy.data.version) < (4, 2)
+        and bpy.app.version >= (4, 2)
+    ):
+        logger.warning(
+            "Migrating Materials from blender version data=%s app=%s",
+            bpy.data.version,
+            bpy.app.version,
+        )
+
+        # Blender 4.2.0ではtimerで実行しないとダイアログが自動で消える
+        bpy.app.timers.register(
+            functools.partial(
+                show_material_blender_4_2_warning_delay,
+                "\n".join(blender_4_2_migrated_material_names),
+            ),
+            first_interval=0,
+        )
 
 
-def migrate_material(context: Context, material: Material) -> None:
+def migrate_material(
+    context: Context,
+    material: Material,
+    blender_4_2_migrated_material_names: list[str],
+) -> None:
     if not material.use_nodes:
         return
     node_tree = material.node_tree
@@ -110,6 +142,7 @@ def migrate_material(context: Context, material: Material) -> None:
     alpha_mode: Optional[str] = None
     alpha_cutoff: Optional[float] = None
     if addon_version < (2, 20, 55):
+        blender_4_2_migrated_material_names.append(material.name)
         alpha_cutoff = material.alpha_threshold
         blend_method = material.blend_method
         if blend_method in ["BLEND", "HASHED"]:
@@ -371,6 +404,8 @@ def migrate_material(context: Context, material: Material) -> None:
             uv_animation_rotation_speed_factor
         )
 
+    typed_mtoon1.addon_version = version.addon_version()
+
 
 def backup_texture_info(texture_info: object) -> Optional[TextureInfoBackup]:
     if not isinstance(texture_info, IDPropertyGroup):

src/io_scene_vrm/editor/mtoon1/ops.py

@@ -6,6 +6,7 @@
 from typing import TYPE_CHECKING, Optional
 
 import bpy
+from bpy.app.translations import pgettext
 from bpy.props import BoolProperty, EnumProperty, StringProperty
 from bpy.types import (
     Context,
@@ -1075,3 +1076,61 @@ def execute(self, context: Context) -> set[str]:
         # `poetry run python tools/property_typing.py`
         material_name: str  # type: ignore[no-redef]
         create_modifier: bool  # type: ignore[no-redef]
+
+
+class VRM_OT_show_material_blender_4_2_warning(Operator):
+    bl_idname = "vrm.show_material_blender_4_2_warning"
+    bl_label = "Blender 4.2 Material Upgrade Warning"
+    bl_description = "Show Material Blender 4.2 Warning"
+    bl_options: AbstractSet[str] = {"REGISTER"}
+
+    material_name_lines: StringProperty(  # type: ignore[valid-type]
+        options={"HIDDEN"}
+    )
+
+    def execute(self, _context: Context) -> set[str]:
+        return {"FINISHED"}
+
+    def invoke(self, context: Context, _event: Event) -> set[str]:
+        return context.window_manager.invoke_props_dialog(self, width=750)
+
+    def draw(self, _context: Context) -> None:
+        column = self.layout.row(align=True).column()
+        text = pgettext(
+            'Updating to Blender 4.2 may unintentionally change the "{alpha_mode}"'
+            + ' of some MToon materials to "{transparent}".\n'
+            + 'This was previously implemented using the material\'s "{blend_mode}"'
+            + " but since that setting was removed in Blender 4.2\n"
+            + 'In the current VRM add-on, the "{alpha_mode}" function has been'
+            + " re-implemented using a different method. However, it\n"
+            + "was not possible"
+            + " to implement automatic migration of old settings values because those"
+            + " values"
+            + " could no longer be read.\n"
+            + 'Please check the "{alpha_mode}" settings for materials that have'
+            + " MToon enabled. "
+            + "Alternatively, if you open and save the \ncurrent file using the latest"
+            + " version of Blender 3.6 and the VRM add-on, the data for automatic"
+            + " migration will be created \ninternally, so that file can be opened in"
+            + " Blender 4.2 or later without losing the material settings.\n"
+            + "Materials that may be affected are as follows:"
+        ).format(
+            blend_mode=pgettext("Blend Mode"),
+            alpha_mode=pgettext("Alpha Mode"),
+            transparent=pgettext("Transparent"),
+        )
+        description_row = column.row()
+        description_row.emboss = "NONE"
+        description_column = description_row.box().column(align=True)
+        for i, line in enumerate(text.splitlines()):
+            icon = "ERROR" if i == 0 else "NONE"
+            description_column.label(text=line, translate=False, icon=icon)
+        material_column = column.box().column(align=True)
+        for line in self.material_name_lines.splitlines():
+            material_column.label(text=line, translate=False, icon="MATERIAL")
+        column.separator()
+
+    if TYPE_CHECKING:
+        # This code is auto generated.
+        # `poetry run python tools/property_typing.py`
+        material_name_lines: str  # type: ignore[no-redef]

src/io_scene_vrm/locale/ja_jp.py

@@ -552,4 +552,41 @@
         + " for humanoid avatars.",
     ): "アーマチュアは人型では無いリグでエクスポートされます。"
     + "人型アバター用のアニメーションが適用されません。",
+    (
+        "Operator",
+        "Blender 4.2 Material Upgrade Warning",
+    ): "Blender 4.2でのマテリアルアップグレードの警告",
+    (
+        "*",
+        'Updating to Blender 4.2 may unintentionally change the "{alpha_mode}"'
+        + ' of some MToon materials to "{transparent}".\n'
+        + 'This was previously implemented using the material\'s "{blend_mode}"'
+        + " but since that setting was removed in Blender 4.2\n"
+        + 'In the current VRM add-on, the "{alpha_mode}" function has been'
+        + " re-implemented using a different method. However, it\n"
+        + "was not possible"
+        + " to implement automatic migration of old settings values because those"
+        + " values"
+        + " could no longer be read.\n"
+        + 'Please check the "{alpha_mode}" settings for materials that have'
+        + " MToon enabled. "
+        + "Alternatively, if you open and save the \ncurrent file using the latest"
+        + " version of Blender 3.6 and the VRM add-on, the data for automatic"
+        + " migration will be created \ninternally, so that file can be opened in"
+        + " Blender 4.2 or later without losing the material settings.\n"
+        + "Materials that may be affected are as follows:",
+    ): "Blender 4.2へのアップデートに伴い、一部のMToonマテリアルの"
+    + "「{alpha_mode}」設定が意図せず「{transparent}」に変化している\n"
+    + "可能性があります。当該機能は今までマテリアルの「{blend_mode}」設定で"
+    + "実装されていましたが、Blender 4.2からその設定が\n"
+    + "削除されたためです。"
+    + "現在のVRMアドオンでは「{alpha_mode}」の機能は別の方式で再実装"
+    + "されましたが、古い設定値の自動移行は、\n"
+    + "古い設定値自体がもう読めないため実装が不可能でした。"
+    + "MToonが有効なマテリアルの「{alpha_mode}」設定の確認をお願いします。\n"
+    + "あるいは、Blender 3.6とVRMアドオンの最新版で現在のファイルを"
+    + "一度開いて保存すると、内部的に自動移行用のデータが作成\n"
+    + "されるため、そのファイルはマテリアルの設定を失わずに"
+    + "Blender 4.2以降でも開けるようになります。\n"
+    + "影響のある可能性のあるマテリアルは次の通りです。",
 }

src/io_scene_vrm/registration.py

@@ -401,6 +401,7 @@ def save_pre(_unused: object) -> None:
     mtoon1_ops.VRM_OT_reset_mtoon1_material_shader_node_tree,
     mtoon1_ops.VRM_OT_import_mtoon1_texture_image_file,
     mtoon1_ops.VRM_OT_refresh_mtoon1_outline,
+    mtoon1_ops.VRM_OT_show_material_blender_4_2_warning,
     detail_mesh_maker.ICYP_OT_detail_mesh_maker,
     glsl_drawer.ICYP_OT_draw_model,
     glsl_drawer.ICYP_OT_remove_draw_model,