glTF exporter: fix shapekeys animation export

Animation channels must be sorted in exactly same order than shapekeys

1 files changed, 31 insertions, 3 deletions

diff --git a/io_scene_gltf2/blender/exp/gltf2_blender_gather_animation_channels.py b/io_scene_gltf2/blender/exp/gltf2_blender_gather_animation_channels.py
index 412f275b..45a75717 100755
--- a/io_scene_gltf2/blender/exp/gltf2_blender_gather_animation_channels.py
+++ b/io_scene_gltf2/blender/exp/gltf2_blender_gather_animation_channels.py
@@ -64,12 +64,35 @@ def gather_animation_channels(blender_action: bpy.types.Action,
                 channels.append(channel)
     else:
         for channel_group in __get_channel_groups(blender_action, blender_object, export_settings):
-            channel = __gather_animation_channel(channel_group, blender_object, export_settings, None, None, None, None, blender_action.name)
+            channel_group_sorted = __get_channel_group_sorted(channel_group, blender_object)
+            channel = __gather_animation_channel(channel_group_sorted, blender_object, export_settings, None, None, None, None, blender_action.name)
             if channel is not None:
                 channels.append(channel)
 
     return channels
 
+def __get_channel_group_sorted(channels: typing.Tuple[bpy.types.FCurve], blender_object: bpy.types.Object):
+    # if this is shapekey animation, we need to sort in same order than shapekeys
+    # else, no need to sort
+    if blender_object.type == "MESH":
+        first_channel = channels[0]
+        object_path = get_target_object_path(first_channel.data_path)
+        if object_path:
+            # This is shapekeys, we need to sort channels
+            shapekeys_idx = {}
+            cpt_sk = 0
+            for sk in blender_object.data.shape_keys.key_blocks:
+                if sk == sk.relative_key:
+                    continue
+                if sk.mute is True:
+                    continue
+                shapekeys_idx[sk.name] = cpt_sk
+                cpt_sk += 1
+
+            return tuple(sorted(channels, key=lambda x: shapekeys_idx[blender_object.data.shape_keys.path_resolve(get_target_object_path(x.data_path)).name]))
+
+    # if not shapekeys, stay in same order, because order doesn't matter
+    return channels
 
 def __gather_animation_channel(channels: typing.Tuple[bpy.types.FCurve],
                                blender_object: bpy.types.Object,
@@ -164,12 +187,17 @@ def __get_channel_groups(blender_action: bpy.types.Action, blender_object: bpy.t
         else:
             try:
                 target = gltf2_blender_get.get_object_from_datapath(blender_object, object_path)
+                if blender_object.type == "MESH":
+                    shape_key = blender_object.data.shape_keys.path_resolve(object_path)
+                    if shape_key.mute is True:
+                        continue
             except ValueError as e:
                 # if the object is a mesh and the action target path can not be resolved, we know that this is a morph
                 # animation.
                 if blender_object.type == "MESH":
-                    # if you need the specific shape key for some reason, this is it:
-                    # shape_key = blender_object.data.shape_keys.path_resolve(object_path)
+                    shape_key = blender_object.data.shape_keys.path_resolve(object_path)
+                    if shape_key.mute is True:
+                        continue
                     target = blender_object.data.shape_keys
                 else:
                     gltf2_io_debug.print_console("WARNING", "Animation target {} not found".format(object_path))