Blender Import BVH file and render this skeleton to make video

Question

I have a private project to import a custom BVH file (motion capture file) and convert it to an animation video. I tried to do it with Blender and want to do this task with no windows of blender (just execute blender - python script).

I tried to import BVH file with bpy.ops.import_anim.bvh and render it. However, there's no object, just background there. How, do I visualize this custom BVH file and render it?

My codes were from https://github.com/DeepMotionEditing/deep-motion-editing/tree/master/blender_rendering

import sys
sys.path.append('./')
import bpy

from options import Options
from load_bvh import load_bvh
from scene import make_scene, add_material_for_character, add_rendering_parameters

if __name__ == '__main__':
    args = Options(sys.argv).parse()

    bpy.ops.object.select_all(action='SELECT')
    bpy.ops.object.delete()
    print(args.bvh_path)
    #character = load_bvh(args.bvh_path)
    bpy.ops.import_anim.bvh(filepath=args.bvh_path, axis_up='Y', axis_forward='-Z', filter_glob="*.bvh", target='ARMATURE', global_scale=10.0, frame_start=1, use_fps_scale=False, use_cyclic=False, rotate_mode='NATIVE')
    scene = make_scene()
    armature = bpy.context.object
    #add_material_for_character(armature)
    bpy.ops.object.select_all(action='DESELECT')

    add_rendering_parameters(bpy.context.scene, args, scene[1])

    if args.render:
        bpy.ops.render.render(animation=True, use_viewport=True)
        exit(0)

What I want to achieve

My current status