glTF exporter: option to export only deformation bones

io_scene_gltf2/__init__.py

@@ -15,7 +15,7 @@
 bl_info = {
     'name': 'glTF 2.0 format',
     'author': 'Julien Duroure, Norbert Nopper, Urs Hanselmann, Moritz Becher, Benjamin Schmithüsen, Jim Eckerlein, and many external contributors',
-    "version": (1, 0, 5),
+    "version": (1, 0, 6),
     'blender': (2, 81, 6),
     'location': 'File > Import-Export',
     'description': 'Import-Export as glTF 2.0',
@@ -257,6 +257,12 @@ class ExportGLTF2_Base:
         default=True
     )
 
+    export_def_bones: BoolProperty(
+        name='Export Deformation bones only',
+        description='Export Deformation bones only (and needed bones for hierarchy)',
+        default=False
+    )
+
     export_current_frame: BoolProperty(
         name='Use Current Frame',
         description='Export the scene in the current animation frame',
@@ -390,11 +396,16 @@ class ExportGLTF2_Base:
         if self.export_animations:
             export_settings['gltf_frame_range'] = self.export_frame_range
             export_settings['gltf_force_sampling'] = self.export_force_sampling
+            if self.export_force_sampling:
+                export_settings['gltf_def_bones'] = self.export_def_bones
+            else:
+                export_settings['gltf_def_bones'] = False
             export_settings['gltf_nla_strips'] = self.export_nla_strips
         else:
             export_settings['gltf_frame_range'] = False
             export_settings['gltf_move_keyframes'] = False
             export_settings['gltf_force_sampling'] = False
+            export_settings['gltf_def_bones'] = False
         export_settings['gltf_skins'] = self.export_skins
         if self.export_skins:
             export_settings['gltf_all_vertex_influences'] = self.export_all_influences
@@ -643,6 +654,10 @@ class GLTF_PT_export_animation_export(bpy.types.Panel):
         layout.prop(operator, 'export_force_sampling')
         layout.prop(operator, 'export_nla_strips')
 
+        row = layout.row()
+        row.active = operator.export_force_sampling
+        row.prop(operator, 'export_def_bones')
+
 
 class GLTF_PT_export_animation_shapekeys(bpy.types.Panel):
     bl_space_type = 'FILE_BROWSER'

io_scene_gltf2/blender/exp/gltf2_blender_gather_animation_channel_target.py

@@ -19,7 +19,7 @@ from io_scene_gltf2.io.com import gltf2_io
 from io_scene_gltf2.blender.exp.gltf2_blender_gather_cache import cached
 from io_scene_gltf2.blender.exp import gltf2_blender_gather_nodes
 from io_scene_gltf2.blender.exp import gltf2_blender_gather_joints
-
+from io_scene_gltf2.blender.exp import gltf2_blender_gather_skins
 
 @cached
 def gather_animation_channel_target(channels: typing.Tuple[bpy.types.FCurve],
@@ -66,7 +66,12 @@ def __gather_node(channels: typing.Tuple[bpy.types.FCurve],
             blender_bone = blender_object.path_resolve(channels[0].data_path.rsplit('.', 1)[0])
 
         if isinstance(blender_bone, bpy.types.PoseBone):
-            return gltf2_blender_gather_joints.gather_joint(blender_bone, export_settings)
+            if export_settings["gltf_def_bones"] is False:
+                return gltf2_blender_gather_joints.gather_joint(blender_bone, export_settings)
+            else:
+                bones, _, _ = gltf2_blender_gather_skins.get_bone_tree(None, blender_object)
+                if blender_bone.name in [b.name for b in bones]:
+                    return gltf2_blender_gather_joints.gather_joint(blender_bone, export_settings)
 
     return gltf2_blender_gather_nodes.gather_node(blender_object, None, export_settings)
 

io_scene_gltf2/blender/exp/gltf2_blender_gather_animation_channels.py

@@ -22,6 +22,7 @@ from io_scene_gltf2.blender.exp.gltf2_blender_gather_cache import cached
 from io_scene_gltf2.blender.exp import gltf2_blender_gather_animation_samplers
 from io_scene_gltf2.blender.exp import gltf2_blender_gather_animation_channel_target
 from io_scene_gltf2.blender.exp import gltf2_blender_get
+from io_scene_gltf2.blender.exp import gltf2_blender_gather_skins
 
 
 @cached
@@ -58,7 +59,14 @@ def gather_animation_channels(blender_action: bpy.types.Action,
             return []
 
         # Then bake all bones
-        for bone in blender_object.data.bones:
+        bones_to_be_animated = []
+        if export_settings["gltf_def_bones"] is False:
+            bones_to_be_animated = blender_object.data.bones
+        else:
+            bones_to_be_animated, _, _ = gltf2_blender_gather_skins.get_bone_tree(None, blender_object)
+            bones_to_be_animated = [blender_object.pose.bones[b.name] for b in bones_to_be_animated]
+
+        for bone in bones_to_be_animated:
             for p in ["location", "rotation_quaternion", "scale"]:
                 channel = __gather_animation_channel(
                     (),

io_scene_gltf2/blender/exp/gltf2_blender_gather_joints.py

@@ -20,6 +20,7 @@ from io_scene_gltf2.io.com import gltf2_io
 from io_scene_gltf2.io.com import gltf2_io_debug
 from io_scene_gltf2.blender.exp import gltf2_blender_extract
 from io_scene_gltf2.blender.com import gltf2_blender_math
+from io_scene_gltf2.blender.exp import gltf2_blender_gather_skins
 
 
 @cached
@@ -55,8 +56,15 @@ def gather_joint(blender_bone, export_settings):
 
     # traverse into children
     children = []
-    for bone in blender_bone.children:
-        children.append(gather_joint(bone, export_settings))
+
+    if export_settings["gltf_def_bones"] is False:
+        for bone in blender_bone.children:
+            children.append(gather_joint(bone, export_settings))
+    else:
+        _, children_, _ = gltf2_blender_gather_skins.get_bone_tree(None, blender_bone.id_data)
+        if blender_bone.name in children_.keys():
+            for bone in children_[blender_bone.name]:
+                children.append(gather_joint(blender_bone.id_data.pose.bones[bone], export_settings))
 
     # finally add to the joints array containing all the joints in the hierarchy
     return gltf2_io.Node(

io_scene_gltf2/blender/exp/gltf2_blender_gather_nodes.py

@@ -135,7 +135,12 @@ def __gather_children(blender_object, blender_scene, export_settings):
     # blender bones
     if blender_object.type == "ARMATURE":
         root_joints = []
-        for blender_bone in blender_object.pose.bones:
+        if export_settings["gltf_def_bones"] is False:
+            bones = blender_object.pose.bones
+        else:
+            bones, _, _ = gltf2_blender_gather_skins.get_bone_tree(None, blender_object)
+            bones = [blender_object.pose.bones[b.name] for b in bones]
+        for blender_bone in bones:
             if not blender_bone.parent:
                 joint = gltf2_blender_gather_joints.gather_joint(blender_bone, export_settings)
                 children.append(joint)

io_scene_gltf2/blender/exp/gltf2_blender_gather_skins.py

@@ -67,11 +67,14 @@ def __gather_inverse_bind_matrices(blender_object, export_settings):
         axis_basis_change = mathutils.Matrix(
             ((1.0, 0.0, 0.0, 0.0), (0.0, 0.0, 1.0, 0.0), (0.0, -1.0, 0.0, 0.0), (0.0, 0.0, 0.0, 1.0)))
 
-    # build the hierarchy of nodes out of the bones
-    root_bones = []
-    for blender_bone in blender_object.pose.bones:
-        if not blender_bone.parent:
-            root_bones.append(blender_bone)
+    if export_settings['gltf_def_bones'] is False:
+        # build the hierarchy of nodes out of the bones
+        root_bones = []
+        for blender_bone in blender_object.pose.bones:
+            if not blender_bone.parent:
+                root_bones.append(blender_bone)
+    else:
+        _, children_, root_bones = get_bone_tree(None, blender_object)
 
     matrices = []
 
@@ -86,8 +89,13 @@ def __gather_inverse_bind_matrices(blender_object, export_settings):
         ).inverted()
         matrices.append(inverse_bind_matrix)
 
-        for child in bone.children:
-            __collect_matrices(child)
+        if export_settings['gltf_def_bones'] is False:
+            for child in bone.children:
+                __collect_matrices(child)
+        else:
+            if bone.name in children_.keys():
+                for child in children_[bone.name]:
+                    __collect_matrices(blender_object.pose.bones[child])
 
     # start with the "root" bones and recurse into children, in the same ordering as the how joints are gathered
     for root_bone in root_bones:
@@ -114,18 +122,28 @@ def __gather_inverse_bind_matrices(blender_object, export_settings):
 
 def __gather_joints(blender_object, export_settings):
     root_joints = []
-    # build the hierarchy of nodes out of the bones
-    for blender_bone in blender_object.pose.bones:
-        if not blender_bone.parent:
-            root_joints.append(gltf2_blender_gather_joints.gather_joint(blender_bone, export_settings))
+    if export_settings['gltf_def_bones'] is False:
+        # build the hierarchy of nodes out of the bones
+        for blender_bone in blender_object.pose.bones:
+            if not blender_bone.parent:
+                root_joints.append(gltf2_blender_gather_joints.gather_joint(blender_bone, export_settings))
+    else:
+        _, children_, root_joints = get_bone_tree(None, blender_object)
+        root_joints = [gltf2_blender_gather_joints.gather_joint(i, export_settings) for i in root_joints]
 
     # joints is a flat list containing all nodes belonging to the skin
     joints = []
 
     def __collect_joints(node):
         joints.append(node)
-        for child in node.children:
-            __collect_joints(child)
+        if export_settings['gltf_def_bones'] is False:
+            for child in node.children:
+                __collect_joints(child)
+        else:
+            if node.name in children_.keys():
+                for child in children_[node.name]:
+                    __collect_joints(gltf2_blender_gather_joints.gather_joint(blender_object.pose.bones[child], export_settings))
+
     for joint in root_joints:
         __collect_joints(joint)
 
@@ -140,3 +158,30 @@ def __gather_skeleton(blender_object, export_settings):
     # In the future support the result of https://github.com/KhronosGroup/glTF/pull/1195
     return None  # gltf2_blender_gather_nodes.gather_node(blender_object, blender_scene, export_settings)
 
+@cached
+def get_bone_tree(blender_dummy, blender_object):
+
+    bones = []
+    children = {}
+    root_bones = []
+
+    def get_parent(bone):
+        bones.append(bone.name)
+        if bone.parent is not None:
+            if bone.parent.name not in children.keys():
+                children[bone.parent.name] = []
+            children[bone.parent.name].append(bone.name)
+            get_parent(bone.parent)
+        else:
+            root_bones.append(bone.name)
+
+    for bone in [b for b in blender_object.data.bones if b.use_deform is True]:
+        get_parent(bone)
+
+    # remove duplicates
+    for k, v in children.items():
+        children[k] = list(set(v))
+    list_ = list(set(bones))
+    root_ = list(set(root_bones))
+    return [blender_object.data.bones[b] for b in list_], children, [blender_object.pose.bones[b] for b in root_]
+