Fix KhronosGroup#354: When importing animation(s), stash any animatio…

…n into NLA

addons/io_scene_gltf2/blender/imp/gltf2_blender_animation.py

@@ -32,3 +32,27 @@ def anim(gltf, anim_idx, node_idx):
         if gltf.data.nodes[node_idx].children:
             for child in gltf.data.nodes[node_idx].children:
                 BlenderAnimation.anim(gltf, anim_idx, child)
+
+    @staticmethod
+    def stash_action(gltf, anim_idx, node_idx, action_name):
+
+        if gltf.data.nodes[node_idx].is_joint:
+            BlenderBoneAnim.stash_action(gltf, anim_idx, node_idx, action_name)
+        else:
+            BlenderNodeAnim.stash_action(gltf, anim_idx, node_idx, action_name)
+
+        if gltf.data.nodes[node_idx].children:
+            for child in gltf.data.nodes[node_idx].children:
+                BlenderAnimation.stash_action(gltf, anim_idx, child, action_name)
+
+    @staticmethod
+    def restore_last_action(gltf, node_idx):
+
+        if gltf.data.nodes[node_idx].is_joint:
+            BlenderBoneAnim.restore_last_action(gltf, node_idx)
+        else:
+            BlenderNodeAnim.restore_last_action(gltf, node_idx)
+
+        if gltf.data.nodes[node_idx].children:
+            for child in gltf.data.nodes[node_idx].children:
+                BlenderAnimation.restore_last_action(gltf, child)

addons/io_scene_gltf2/blender/imp/gltf2_blender_animation_bone.py

@@ -18,6 +18,7 @@
 
 from ..com.gltf2_blender_conversion import loc_gltf_to_blender, quaternion_gltf_to_blender, scale_to_matrix
 from ...io.imp.gltf2_io_binary import BinaryData
+from .gltf2_blender_animation_utils import simulate_stash, restore_last_action
 
 
 class BlenderBoneAnim():
@@ -39,6 +40,30 @@ def set_interpolation(interpolation, kf):
         else:
             kf.interpolation = 'LINEAR'
 
+    @staticmethod
+    def stash_action(gltf, anim_idx, node_idx, action_name):
+        node = gltf.data.nodes[node_idx]
+        obj = bpy.data.objects[gltf.data.skins[node.skin_id].blender_armature_name]
+
+        if anim_idx not in node.animations.keys():
+            return
+
+        if (obj.name, action_name) in gltf.actions_stashed.keys():
+            return
+
+        start_frame = bpy.context.scene.frame_start
+
+        simulate_stash(obj, bpy.data.actions[action_name], start_frame)
+
+        gltf.actions_stashed[(obj.name, action_name)] = True
+
+    @staticmethod
+    def restore_last_action(gltf, node_idx):
+        node = gltf.data.nodes[node_idx]
+        obj = bpy.data.objects[gltf.data.skins[node.skin_id].blender_armature_name]
+
+        restore_last_action(obj)
+
     @staticmethod
     def parse_translation_channel(gltf, node, obj, bone, channel, animation):
         """Manage Location animation."""

addons/io_scene_gltf2/blender/imp/gltf2_blender_animation_node.py

@@ -18,6 +18,7 @@
 from ..com.gltf2_blender_conversion import loc_gltf_to_blender, quaternion_gltf_to_blender, scale_gltf_to_blender
 from ..com.gltf2_blender_conversion import correction_rotation
 from ...io.imp.gltf2_io_binary import BinaryData
+from .gltf2_blender_animation_utils import simulate_stash, restore_last_action
 
 
 class BlenderNodeAnim():
@@ -39,6 +40,30 @@ def set_interpolation(interpolation, kf):
         else:
             kf.interpolation = 'LINEAR'
 
+    @staticmethod
+    def stash_action(gltf, anim_idx, node_idx, action_name):
+        node = gltf.data.nodes[node_idx]
+        obj = bpy.data.objects[node.blender_object]
+
+        if anim_idx not in node.animations.keys():
+            return
+
+        if (obj.name, action_name) in gltf.actions_stashed.keys():
+            return
+
+        start_frame = bpy.context.scene.frame_start
+
+        simulate_stash(obj, bpy.data.actions[action_name], start_frame)
+
+        gltf.actions_stashed[(obj.name, action_name)] = True
+
+    @staticmethod
+    def restore_last_action(gltf, node_idx):
+        node = gltf.data.nodes[node_idx]
+        obj = bpy.data.objects[node.blender_object]
+
+        restore_last_action(obj)
+
     @staticmethod
     def anim(gltf, anim_idx, node_idx):
         """Manage animation."""

addons/io_scene_gltf2/blender/imp/gltf2_blender_animation_utils.py

@@ -0,0 +1,38 @@
+# Copyright 2019 The glTF-Blender-IO authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+def simulate_stash(obj, action, start_frame):
+    # Simulate stash :
+    # * add a track
+    # * add an action on track
+    # * lock & mute the track
+    # * remove active action from object
+    tracks = obj.animation_data.nla_tracks
+    new_track = tracks.new(prev=None)
+    new_track.name = action.name
+    strip = new_track.strips.new(action.name, start_frame, action)
+    new_track.lock = True
+    new_track.mute = True
+    obj.animation_data.action = None
+
+def restore_last_action(obj):
+
+    if not obj.animation_data:
+        return
+    tracks = obj.animation_data.nla_tracks
+    if len(tracks) == 0:
+        return
+    if len(tracks[0].strips) == 0:
+        return
+    obj.animation_data.action = tracks[0].strips[0].action

addons/io_scene_gltf2/blender/imp/gltf2_blender_scene.py

@@ -117,11 +117,16 @@ def create(gltf, scene_idx):
             gltf.animation_managed = []
             for anim_idx, anim in enumerate(gltf.data.animations):
                 gltf.current_animation_names = {}
+                gltf.actions_stashed= {}
                 if list_nodes is not None:
                     for node_idx in list_nodes:
                         BlenderAnimation.anim(gltf, anim_idx, node_idx)
                 for an in gltf.current_animation_names.values():
                     gltf.animation_managed.append(an)
+                    for node_idx in list_nodes:
+                        BlenderAnimation.stash_action(gltf, anim_idx, node_idx, an)
+            for node_idx in list_nodes:
+                BlenderAnimation.restore_last_action(gltf, node_idx)
 
         if bpy.app.debug_value != 100:
             # Parent root node to rotation object