Implement .blend asset processor (#56)

Reviewed-on: #56
Co-authored-by: Álex Román Núñez <eirexe@eirteam.moe>

src/blend_asset/export.py

@@ -0,0 +1,71 @@
+import bpy
+import json
+import os
+import sys
+
+
+def main():
+    output = sys.argv[sys.argv.index("--") + 1]
+    actions_path = sys.argv[sys.argv.index("--") + 2]
+    with open(actions_path) as file:
+        actions_to_keep = set(json.load(file))
+
+    for obj in bpy.data.objects:
+        if not obj.animation_data:
+            continue
+        for track in list(obj.animation_data.nla_tracks):
+            if track.name.startswith("[Action Stash]"):
+                obj.animation_data.nla_tracks.remove(track)
+
+    nla_tracks = [
+        track
+        for obj in bpy.data.objects
+        if obj.animation_data
+        for track in obj.animation_data.nla_tracks
+    ]
+    use_nla_tracks = bool(nla_tracks)
+
+    # For blends without NLA tracks, use the actions referenced by the fighter
+    # manifest instead of sampling every source action.
+    if not use_nla_tracks and actions_to_keep:
+        from io_scene_gltf2 import GLTF2_filter_action
+
+        if not hasattr(bpy.types.Scene, "gltf_action_filter"):
+            bpy.types.Scene.gltf_action_filter = bpy.props.CollectionProperty(
+                type=GLTF2_filter_action
+            )
+        scene = bpy.context.scene
+        scene.gltf_action_filter.clear()
+        for action in bpy.data.actions:
+            item = scene.gltf_action_filter.add()
+            item.action = action
+            item.keep = action.name in actions_to_keep
+
+    bpy.ops.export_scene.gltf(
+        filepath=output,
+        export_format="GLTF_SEPARATE",
+        export_keep_originals=True,
+        export_extras=True,
+        export_animations=True,
+        export_skins=True,
+        export_morph=True,
+        export_yup=True,
+        export_def_bones=True,
+        export_action_filter=False,
+        export_animation_mode="NLA_TRACKS" if use_nla_tracks else "ACTIONS",
+    )
+
+    dependencies = []
+    for image in bpy.data.images:
+        if image.source not in {"FILE", "TILED"}:
+            continue
+        path = image.filepath_raw or image.filepath
+        if path and not image.packed_file:
+            dependencies.append(bpy.path.abspath(path))
+
+    with open(os.path.join(os.path.dirname(output), "export-manifest.json"), "w") as file:
+        json.dump({"dependencies": sorted(set(dependencies))}, file)
+
+
+if __name__ == "__main__":
+    main()