Body

Load

def load_model_to_scene(model_file, s=1.0):
    # We assume that the model name is Armature, need to change the name if it's different
    
    bpy.ops.import_scene.fbx(filepath=model_file, axis_forward='Y', axis_up='Z')

    hmodel = bpy.data.objects["Armature"]
    hmodel.scale = Vector((s,s,s))		

    return hmodel

Shape

bpy.ops.avt.reset_params()

model.val_breast = val   # breast values goes from 0 to 1
model.val_torso = np.random.exponential(2, 1)  # torso values goes from -0.3 to 0.3
model.val_limbs = val  # limbs values goes from 0 to 1
model.val_hips = val # hips values goes from 0 to 1
model.val_strength = val # strength values goes from 0 to 0.5
model.val_weight = val # weight values goes from -0.5 to 1.5

bpy.ops.avt.set_body_shape()

import bpy
import numpy as np
import random


out_path = "/some/user/path"

model = bpy.data.objects["Avatar"]

scene = bpy.context.scene

bpy.ops.avt.reset_params()

for f in range(100):
    
    print(f)

    model.val_breast = random.uniform(0, 1)
    model.val_weight = random.uniform(0, 1)
    model.val_hips = random.uniform(0, 1)

    bpy.ops.avt.set_body_shape()
    
    # set output path so render won't get overwritten
    scene.render.filepath = "%s/%04d.jpg" % (out_path, f)
    bpy.ops.render.render(write_still=True) # render still

Pose

List of Avatar joints. For some reason, if you save different models and load them again, blender modifies the joint order, so it is important to read them from a list or sort joints to obtain them always in the same order.

bones_avatar_rig = ["Hips", "LHipJoint", "LeftUpLeg", "LeftLeg", "LeftFoot", "LeftToeBase", "LowerBack",
                    "Spine", "Spine1", "LeftShoulder", "LeftArm", "LeftForeArm", "LeftHand", "LThumb",
                    "LeftFingerBase", "LeftHandFinger1", "Neck", "Neck1", "Head", "RightShoulder", 
                    "RightArm", "RightForeArm", "RightHand", "RThumb", "RightFingerBase", "RightHandFinger1",
                    "RHipJoint", "RightUpLeg", "RightLeg", "RightFoot", "RightToeBase", "HeadTop"]

def get_bone_head_position(obj, bone_name):
    return (obj.matrix_world @ Matrix.Translation(obj.pose.bones[bone_name].head)).to_translation()

def get_bone_tail_position(obj, bone_name):
    return (obj.matrix_world @ Matrix.Translation(obj.pose.bones[bone_name].tail)).to_translation()

Load BVH file with avatar addon. First if you are using avatar functions. Second if you use BVH add-on.

bpy.ops.avt.load_bvh(filepath=motion_file)

bpy.ops.mcp.load_and_retarget(filepath=action_file)