Added a docstring for populate_bone_group_list

This brings back the old behavior (before 1ac0870) where all groups
are selected by default.

io_scene_psk_psa/helpers.py

@@ -1,8 +1,9 @@
 import datetime
 from collections import Counter
-from typing import List
+from typing import List, Iterable
 
-from bpy.types import NlaStrip
+from bpy.types import NlaStrip, Object
+from .types import BoneGroupListItem
 
 
 class Timer:
@@ -56,7 +57,26 @@ def get_nla_strips_in_timeframe(object, frame_min, frame_max) -> List[NlaStrip]:
     return strips
 
 
-def populate_bone_group_list(armature_object, bone_group_list):
+def populate_bone_group_list(armature_object: Object, bone_group_list: Iterable[BoneGroupListItem]) -> None:
+    """
+    Updates the bone group collection.
+
+    Bone group selections are preserved between updates unless none of the groups were previously selected;
+    otherwise, all groups are selected by default.
+    """
+    has_selected_groups = any([g.is_selected for g in bone_group_list])
+    unassigned_group_is_selected, selected_assigned_group_names = True, []
+
+    if has_selected_groups:
+        # Preserve group selections before clearing the list.
+        # We handle selections for the unassigned group separately to cover the edge case
+        # where there might be an actual group with 'Unassigned' as its name.
+        unassigned_group_idx, unassigned_group_is_selected = next(iter([
+            (i, g.is_selected) for i, g in enumerate(bone_group_list) if g.index == -1]), (-1, False))
+
+        selected_assigned_group_names = [
+            g.name for i, g in enumerate(bone_group_list) if i != unassigned_group_idx and g.is_selected]
+
     bone_group_list.clear()
 
     if armature_object and armature_object.pose:
@@ -66,14 +86,14 @@ def populate_bone_group_list(armature_object, bone_group_list):
         item.name = 'Unassigned'
         item.index = -1
         item.count = 0 if None not in bone_group_counts else bone_group_counts[None]
-        item.is_selected = True
+        item.is_selected = unassigned_group_is_selected
 
         for bone_group_index, bone_group in enumerate(armature_object.pose.bone_groups):
             item = bone_group_list.add()
             item.name = bone_group.name
             item.index = bone_group_index
             item.count = 0 if bone_group not in bone_group_counts else bone_group_counts[bone_group]
-            item.is_selected = True
+            item.is_selected = bone_group.name in selected_assigned_group_names if has_selected_groups else True
 
 
 def get_psa_sequence_name(action, should_use_original_sequence_name):

io_scene_psk_psa/psa/builder.py

@@ -1,6 +1,7 @@
 from typing import Dict, Iterable
 
 from bpy.types import Action
+from mathutils import Matrix
 
 from .data import *
 from ..helpers import *
@@ -19,13 +20,7 @@ class PsaBuilderOptions(object):
         self.should_trim_timeline_marker_sequences = True
         self.sequence_name_prefix = ''
         self.sequence_name_suffix = ''
-
+        self.root_motion = False
-
-class PsaBuilderPerformance:
-    def __init__(self):
-        self.frame_set_duration = datetime.timedelta()
-        self.key_build_duration = datetime.timedelta()
-        self.key_add_duration = datetime.timedelta()
 
 
 class PsaBuilder(object):
@@ -53,7 +48,6 @@ class PsaBuilder(object):
             raise RuntimeError(f'Invalid FPS source "{options.fps_source}"')
 
     def build(self, context, options: PsaBuilderOptions) -> Psa:
-        performance = PsaBuilderPerformance()
         active_object = context.view_layer.objects.active
 
         if active_object.type != 'ARMATURE':
@@ -201,26 +195,27 @@ class PsaBuilder(object):
             frame_count = frame_max - frame_min + 1
 
             for frame in range(frame_count):
-                with Timer() as t:
                 context.scene.frame_set(frame_min + frame)
-                performance.frame_set_duration += t.duration
 
                 for pose_bone in pose_bones:
-                    with Timer() as t:
                     key = Psa.Key()
-                        pose_bone_matrix = pose_bone.matrix
 
                     if pose_bone.parent is not None:
+                        pose_bone_matrix = pose_bone.matrix
                         pose_bone_parent_matrix = pose_bone.parent.matrix
                         pose_bone_matrix = pose_bone_parent_matrix.inverted() @ pose_bone_matrix
+                    else:
+                        if options.root_motion:
+                            # Export root motion
+                            pose_bone_matrix = armature.matrix_world @ pose_bone.matrix
+                        else:
+                            pose_bone_matrix = pose_bone.matrix
 
                     location = pose_bone_matrix.to_translation()
                     rotation = pose_bone_matrix.to_quaternion().normalized()
 
                     if pose_bone.parent is not None:
-                            rotation.x = -rotation.x
+                        rotation.conjugate()
-                            rotation.y = -rotation.y
-                            rotation.z = -rotation.z
 
                     key.location.x = location.x
                     key.location.y = location.y
@@ -230,11 +225,8 @@ class PsaBuilder(object):
                     key.rotation.z = rotation.z
                     key.rotation.w = rotation.w
                     key.time = 1.0 / psa_sequence.fps
-                    performance.key_build_duration += t.duration
 
-                    with Timer() as t:
                     psa.keys.append(key)
-                    performance.key_add_duration += t.duration
 
                 psa_sequence.bone_count = len(pose_bones)
                 psa_sequence.track_time = frame_count
@@ -264,8 +256,12 @@ class PsaBuilder(object):
                 frame_max = sorted_timeline_markers[next_marker_index].frame
                 if options.should_trim_timeline_marker_sequences:
                     nla_strips = get_nla_strips_in_timeframe(object, marker.frame, frame_max)
+                    if len(nla_strips) > 0:
                         frame_max = min(frame_max, max(map(lambda nla_strip: nla_strip.frame_end, nla_strips)))
                         frame_min = max(frame_min, min(map(lambda nla_strip: nla_strip.frame_start, nla_strips)))
+                    else:
+                        # No strips in between this marker and the next, just export this as a one-frame animation.
+                        frame_max = frame_min
             else:
                 # There is no next marker.
                 # Find the final frame of all the NLA strips and use that as the last frame of this sequence.

io_scene_psk_psa/psa/exporter.py

@@ -65,6 +65,12 @@ def should_use_original_sequence_names_updated(_, context):
 
 
 class PsaExportPropertyGroup(PropertyGroup):
+    root_motion: BoolProperty(
+        name='Root Motion',
+        options=set(),
+        default=False,
+        description='When set, the root bone will be transformed as it appears in the scene',
+    )
     sequence_source: EnumProperty(
         name='Source',
         options=set(),
@@ -165,6 +171,9 @@ class PsaExportOperator(Operator, ExportHelper):
         # SOURCE
         layout.prop(pg, 'sequence_source', text='Source')
 
+        # ROOT MOTION
+        layout.prop(pg, 'root_motion', text='Root Motion')
+
         # SELECT ALL/NONE
         row = layout.row(align=True)
         row.label(text='Select')
@@ -297,6 +306,7 @@ class PsaExportOperator(Operator, ExportHelper):
         options.should_trim_timeline_marker_sequences = pg.should_trim_timeline_marker_sequences
         options.sequence_name_prefix = pg.sequence_name_prefix
         options.sequence_name_suffix = pg.sequence_name_suffix
+        options.root_motion = pg.root_motion
 
         builder = PsaBuilder()