Add a weapon bone to synty models

synty_weapon.py

import sys
import argparse
import pathlib
import subprocess
import os
import time
from mathutils import Vector
import math
try:
    import bpy
except ImportError:
    bpy = None

def add_bone(parent_bone, new_bone):
    bpy.ops.object.editmode_toggle()
    armature = bpy.context.active_object
    bones = armature.data.edit_bones
    right_hand = bones[parent_bone]
    wep_bone = bones.new(new_bone)
    wep_bone.head = right_hand.tail
    wep_bone.tail = wep_bone.head + Vector([0, 0.01, 0])
    wep_bone.parent = right_hand
    bpy.ops.object.editmode_toggle()

# first, convert the FBX files to binary (https://www.autodesk.com/developer-network/platform-technologies/fbx-converter-archives)
# adapted from https://gist.github.com/wojtossfm/cd0808a35753341036fef8efec7704ce
# blender --python synty_weapon.py -- <directory_of_meshes> <output_directory>
# When importing into unreal, remember to import normals
def main_blender(raw_args):
    parser = argparse.ArgumentParser()
    parser.add_argument('fbx')
    parser.add_argument('outdir')
    args = parser.parse_args(raw_args)

    # In the future I want this to support processing a directory (all files from it)
    # but for now they end up with altered names so that is why this does them only one per invocation
    target = pathlib.Path(args.fbx)
    if target.is_dir():
        files = [path for path in target.iterdir() if path.suffix == '.fbx' and not path.stem.endswith('_fixed')]
    else:
        files = [target]

    for filepath in files:
        inpath = str(filepath)
        file_name = "SKO" + filepath.stem.removeprefix("SK") + ".fbx" 
        outpath = str(os.path.join(args.outdir, file_name))

        bpy.ops.object.select_all(action='SELECT')
        bpy.ops.object.delete()

        bpy.ops.import_scene.fbx(filepath=inpath, use_anim=False, ignore_leaf_bones=False, force_connect_children=True, automatic_bone_orientation=False, use_custom_normals=False)
        bpy.ops.object.posemode_toggle()
        bpy.ops.pose.transforms_clear()
        bpy.ops.object.posemode_toggle()

        bpy.context.active_object.rotation_euler = Vector([0,0,0])
        bpy.ops.object.transform_apply(location=True, rotation=True, scale=True, properties=True)
        bpy.context.active_object.rotation_euler = Vector([math.radians(90), 0, 0])
        
        # Add the weapon bone
        add_bone("Hand_R", "Weapon_R")
        add_bone("Hand_L", "Weapon_L")

        bpy.ops.export_scene.fbx(filepath=outpath, add_leaf_bones=False, bake_anim=False, apply_unit_scale=True, mesh_smooth_type="EDGE")


def main():
    try:
        raw_args = sys.argv[sys.argv.index('--') + 1:]
    except ValueError:
        raw_args = []
    main_blender(raw_args)


if __name__ == "__main__":
    main()