glTF exporter: Merge animations into glTF animation(s) based on NLA track names

Option "NLA tracks" is active by default. If disable, all active action of scene will be merge into a single glTF animation

1 files changed, 56 insertions, 2 deletions

diff --git a/io_scene_gltf2/blender/exp/gltf2_blender_gather.py b/io_scene_gltf2/blender/exp/gltf2_blender_gather.py
index 4d28a4bd..92fa9ce2 100755
--- a/io_scene_gltf2/blender/exp/gltf2_blender_gather.py
+++ b/io_scene_gltf2/blender/exp/gltf2_blender_gather.py
@@ -15,6 +15,7 @@
 import bpy
 
 from io_scene_gltf2.io.com import gltf2_io
+from io_scene_gltf2.io.com.gltf2_io_debug import print_console
 from io_scene_gltf2.blender.exp import gltf2_blender_gather_nodes
 from io_scene_gltf2.blender.exp import gltf2_blender_gather_animations
 from io_scene_gltf2.blender.exp.gltf2_blender_gather_cache import cached
@@ -60,12 +61,65 @@ def __gather_scene(blender_scene, export_settings):
 
 def __gather_animations(blender_scene, export_settings):
     animations = []
+    merged_tracks = {}
+
     for blender_object in blender_scene.objects:
         # First check if this object is exported or not. Do not export animation of not exported object
         obj_node = gltf2_blender_gather_nodes.gather_node(blender_object, blender_scene, export_settings)
         if obj_node is not None:
-            animations += gltf2_blender_gather_animations.gather_animations(blender_object, export_settings)
-    return animations
+            animations_, merged_tracks = gltf2_blender_gather_animations.gather_animations(blender_object, merged_tracks, len(animations), export_settings)
+            animations += animations_
+
+    if export_settings['gltf_nla_strips'] is False:
+        # Fake an animation witha all animations of the scene
+        merged_tracks = {}
+        merged_tracks['Animation'] = []
+        for idx, animation in enumerate(animations):
+            merged_tracks['Animation'].append(idx)
+
+
+    to_delete_idx = []
+    for merged_anim_track in merged_tracks.keys():
+        if len(merged_tracks[merged_anim_track]) < 2:
+            continue
+
+        base_animation_idx = None
+        offset_sampler = 0
+
+        for idx, anim_idx in enumerate(merged_tracks[merged_anim_track]):
+            if idx == 0:
+                base_animation_idx = anim_idx
+                animations[anim_idx].name = merged_anim_track
+                already_animated = []
+                for channel in animations[anim_idx].channels:
+                    already_animated.append((channel.target.node, channel.target.path))
+                continue
+
+            to_delete_idx.append(anim_idx)
+
+            offset_sampler = len(animations[base_animation_idx].samplers)
+            for sampler in animations[anim_idx].samplers:
+                animations[base_animation_idx].samplers.append(sampler)
+
+            for channel in animations[anim_idx].channels:
+                if (channel.target.node, channel.target.path) in already_animated:
+                    print_console("WARNING", "Some strips have same channel animation ({}), on node {} !".format(channel.target.path, channel.target.node.name))
+                    continue
+                animations[base_animation_idx].channels.append(channel)
+                animations[base_animation_idx].channels[-1].sampler = animations[base_animation_idx].channels[-1].sampler + offset_sampler
+                already_animated.append((channel.target.node, channel.target.path))
+
+    new_animations = []
+    if len(to_delete_idx) != 0:
+        for idx, animation in enumerate(animations):
+            if idx in to_delete_idx:
+                continue
+            new_animations.append(animation)
+    else:
+        new_animations = animations
+
+
+    return new_animations
 
 
 def __gather_extras(blender_object, export_settings):