From a614e900557773486e3c9484d41d5060d0e12c5d Mon Sep 17 00:00:00 2001
From: Bart Moyaers <bart.moyaers@kuleuven.be>
Date: Tue, 2 Jun 2020 17:17:02 +0200
Subject: [PATCH] correct finger rotation

---
 source/move.py | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/source/move.py b/source/move.py
index e20dc07..99c8fe0 100644
--- a/source/move.py
+++ b/source/move.py
@@ -1,5 +1,6 @@
 import bpy
 from random import random
+from mathutils import Matrix, Quaternion
 
 ob = bpy.data.objects['Sphere']
 frame_number = 0
@@ -14,7 +15,7 @@ thumb_rot_bone = "thumb_3"
 def grab_movement(open):
     # Todo:
     #  select the 4 base finger bones
-    #  Then: bpy.ops.transform.rotate(value=0.1, orient_axis='X', orient_type='LOCAL')
+    #  Then:
     #  To rotate around local axis (will cause to grab)
     #  Then do the same with thumb, but only around local Z axis!
     bpy.ops.object.mode_set(mode='OBJECT')
@@ -29,20 +30,22 @@ def grab_movement(open):
     else:
         angle = 0.8
     
-    # Select all fingers
+    # Deselect all fingers
     for bone in arm.pose.bones:    # Deselect all selected bones
         bone.bone.select = False
+    
+    # Rotate fingers
     for name in finger_grab_bones:
-        bone = arm.pose.bones.get(name).bone
-        #if bone: bone.select = True
+        bone = arm.pose.bones.get(name)
+        # Bones need to be selected when adding keyframes, otherwise blender will throw an error:
+        # https://blender.stackexchange.com/questions/1828/what-constitutes-a-context-in-pose-mode
+        bone.bone.select = True
         # rotate
-        # TODO: change to posebone X axis instead of world X.l
         axis = bone.x_axis
-        bone.rotation_euler = (obj.rotation_euler.to_matrix() * Matrix.Rotation(angle, 3, 'X')).to_euler()
-        #bpy.ops.transform.rotate(value=angle, orient_axis=axis, orient_type='LOCAL')
-        
-    
+        bone.rotation_quaternion = bone.rotation_quaternion @ Quaternion(axis, angle)
+        # bone.matrix = bone.matrix @ Matrix.Rotation(-angle, 4, axis)
     
+    # Add keyframe
     bpy.ops.anim.keying_set_active_set(type='Rotation')
     bpy.ops.anim.keyframe_insert(type='Rotation')
     
@@ -57,6 +60,11 @@ def grab_movement(open):
 
 # Script start
 open = False
+#if len(bpy.data.scenes['Scene'].keying_sets) == 0:
+#    # Add new keying set
+#    bpy.ops.anim.keying_set_add()
+#    # Activate keying set
+#    bpy.ops.anim.keying_set_active_set()
 
 for i in range(50):
     x = random()*max_dist