python script for multi-bone keyframe_insert

Question

I am working on a script that I'd like to share and ask for anyone willing to collaborate on making this an add-on, as I have no experience with add-ons (my last ignorant attempt failed).

workflow motivation: I often have scenes with several rigged characters that I'd like to add additional keyframes to continue an animation. An example might be a sequence where I've animated a couple facing each other who want to lean in and kiss while one touching a shoulder for balance. Or a fight sequence for you more violent types, LOL. So at "new frame" I would put all armatures in pose mode, make adjustments, and then be able to find and key all changed bones (generally IK bone position/rotation, but perhaps FK bones also).

Thus far I have a raw script (no class or method defs), that will look for rotation and location changes in bones from a previous frame's animation value, and add keyframes for any changed FCurve indices.

Possible enhancements:

• insert keyframe for all indices (XYZ) even if only one has changed.
• For any changed bones that do not have a previous keyframe on a bone, insert the initial keyframe values at frame 1 and also the keyframe at frame_current.
• wrap into an add-on and publish

It is the last "wrap" task that I feel rather incapable (lost too much hair in hair pulling last time around).

I appreciate any criticisms or help!

Example test file with script:

I provide my script below in the answer section. I'm going to wager that there's already something existing out there!

Answer 1

Here is my script thus far:

bl_info = {
    "name": "Insert Multiple Bone Keys",
    "author": "Tomkinson",
    "version": (1, 0),
    "blender": (2, 80, 0),
    "location": "View3D > Pose",
    "description": "Add keys to any transformed bones",
    "warning": "",
    "doc_url": "",
    "category": "Animation",
}

import bpy

################################################################################################
# for several bones in selected object armatures, add keys to any bones with changed transforms
################################################################################################

class MY_MT_MultiKeyInserts(bpy.types.Operator):
    """add keys to any bones with changed transforms"""
    bl_idname = "pose.multi_key_inserts"
    bl_label = "Add keys to any transformed bones"
    bl_description = "add keys to any bones with changed transforms" 
    
#    @classmethod
#    def poll(cls, context):
#        return (context.active_object is not None) and (context.active_object is 'ARMATURE')

    def draw(self, context):
        layout = self.layout
        
    def execute(cls, context):
        for o in bpy.context.selected_objects:
            if o.type!= 'ARMATURE':
                continue
            arm = o.data
            for ag in o.animation_data.action.groups:
                pb = o.pose.bones[ ag.name ]
                for fc in ag.channels:  # n-rotation, 3-location, 3-scale, or any that exist
                    fc_Idx = fc.array_index
                    if fc.driver != None:
                        continue
                    
                    fcPsthDotSplit = fc.data_path.split('.')  # location, rotation, scale
                    fcPoseName = fcPsthDotSplit[ len(fcPsthDotSplit) - 1 ]
                    
                    values = fc.keyframe_points.values()
                    last_keyframe = values[len(values)-1]
                    # time:
                    last_time = last_keyframe.co.x
                    # value:
                    last_value = last_keyframe.co.y
                    
                    if fcPoseName.find('location')!=-1:                
                        if fc_Idx>2:
                            continue
                        locA = pb.location[fc_Idx]
                        if ( locA != last_value ):
                            print( o.name, ag.name, fc.data_path, last_value, locA, fc_Idx )
                            pb.keyframe_insert( 'location', index=fc_Idx )
                            
                    elif fcPoseName.find('rotation')!=-1:
                        rmode = pb.rotation_mode
                        rotA = None
                        type = None
                        match rmode:            
                            case 'QUATERNION':
                                rotA = pb.rotation_quaternion[fc_Idx]
                                type = 'rotation_quaternion'
                                        
                            case 'AXIS_ANGLE':
                                rotA = pb.rotation_axis_angle[fc_Idx]
                                type = 'rotation_axis_angle'
                                
                            case _: # one of several Euler types
                                # verify one of several Euler type
                                if (rmode.find('X')!=-1) and (rmode.find('Y')!=-1) and (rmode.find('Z')!=-1):
                                    if fc_Idx>2:   ## sometimes a fourth (idx=3) is keyed, possible due to a QUATERNION to Euler conversion
                                        continue
                                    rotA = pb.rotation_euler[fc_Idx]
                                    type = 'rotation_euler'
                                else:
                                    print( 'unknown rotation type', o.name, pb.name, rmode )
                        
                        if ( type != None ):
                            if rotA != last_value :
                             print( o.name, ag.name, fc.data_path, rmode, type, fc_Idx, last_value, rotA )
                             pb.keyframe_insert( type, index=fc_Idx )
            return {'FINISHED'}

def menu_func(self, context):
    self.layout.operator( MY_MT_MultiKeyInserts.bl_idname, text="Add keys to any transformed bones" )

def register():
    bpy.utils.register_class( MY_MT_MultiKeyInserts )
    bpy.types.VIEW3D_MT_pose_context_menu.append( menu_func )
    bpy.types.VIEW3D_MT_pose.append( menu_func )

def unregister():
    bpy.types.VIEW3D_MT_pose_context_menu.remove( menu_func )
    bpy.types.VIEW3D_MT_pose.remove( menu_func )
    bpy.utils.unregister_class( MY_MT_MultiKeyInserts )

if __name__ == "__main__":
    register()