A python script that converts models generated by SAM-3D-Body to the USDZ file format using blender.

main.py

import bpy
import os
import math
import shutil

# --- CONFIGURATION ---
SOURCE_FOLDER = "/Users/name/.../models_original/"
EXPORT_FOLDER = "/Users/name/.../usdz/"

OBJECTS_TO_KEEP = ["HumanMesh"]
MATCH_LOOSELY = True

WRAPPER_ROTATION = (0, 180, 135) 
TARGET_COLOR = (0.92, 0.92, 0.92, 1.0)
# ------------------------------


def clear_scene():
    if bpy.context.active_object and bpy.context.active_object.mode == "EDIT":
        bpy.ops.object.mode_set(mode="OBJECT")
    bpy.ops.object.select_all(action="SELECT")
    bpy.ops.object.delete()
    for block in bpy.data.meshes:
        if block.users == 0:
            bpy.data.meshes.remove(block)
    for block in bpy.data.armatures:
        if block.users == 0:
            bpy.data.armatures.remove(block)
    for block in bpy.data.objects:
        if block.users == 0:
            bpy.data.objects.remove(block)
    for block in bpy.data.materials:
        if block.users == 0:
            bpy.data.materials.remove(block)


def make_materials_solid_and_dark(obj):
    """Forces material to be Opaque and Darker"""
    for slot in obj.material_slots:
        mat = slot.material
        if not mat:
            continue

        mat.blend_method = "OPAQUE"
        if hasattr(mat, "shadow_method"):
            mat.shadow_method = "OPAQUE"
        mat.use_backface_culling = False

        if getattr(mat, "use_nodes", False):
            nodes = mat.node_tree.nodes
            principled = next((n for n in nodes if n.type == "BSDF_PRINCIPLED"), None)

            if principled:
                if "Alpha" in principled.inputs:
                    principled.inputs["Alpha"].default_value = 1.0

                if "Transmission" in principled.inputs:
                    principled.inputs["Transmission"].default_value = 0.0
                if "Transmission Weight" in principled.inputs:
                    principled.inputs["Transmission Weight"].default_value = 0.0

                color_input = None
                if "Base Color" in principled.inputs:
                    color_input = principled.inputs["Base Color"]
                elif "Color" in principled.inputs:
                    color_input = principled.inputs["Color"]

                if color_input:
                    if not color_input.is_linked:
                        color_input.default_value = TARGET_COLOR


def process_files():
    if os.path.exists(EXPORT_FOLDER):
        shutil.rmtree(EXPORT_FOLDER)
    os.makedirs(EXPORT_FOLDER)

    files = [
        f
        for f in os.listdir(SOURCE_FOLDER)
        if f.lower().endswith((".fbx", ".obj", ".glb", ".gltf"))
    ]
    print(f"Found {len(files)} files to process...")

    for filename in files:
        filepath = os.path.join(SOURCE_FOLDER, filename)
        clear_scene()
        print(f"Processing: {filename}")

        try:
            if filename.lower().endswith(".fbx"):
                bpy.ops.import_scene.fbx(filepath=filepath)
            elif filename.lower().endswith(".obj"):
                bpy.ops.import_scene.obj(filepath=filepath)
            elif filename.lower().endswith((".glb", ".gltf")):
                bpy.ops.import_scene.gltf(filepath=filepath)
        except Exception as e:
            print(f"Error importing {filename}: {e}")
            continue

        kept_objects = []
        for obj in bpy.data.objects:
            is_target = False
            for keep_name in OBJECTS_TO_KEEP:
                if MATCH_LOOSELY:
                    if obj.name.startswith(keep_name):
                        is_target = True
                else:
                    if obj.name == keep_name:
                        is_target = True

            if is_target:
                kept_objects.append(obj)

        bpy.ops.object.select_all(action="DESELECT")
        for obj in bpy.data.objects:
            if obj not in kept_objects:
                obj.select_set(True)
        bpy.ops.object.delete()

        for obj in kept_objects:
            if obj.type == "MESH":
                make_materials_solid_and_dark(obj)

        if kept_objects:
            bpy.ops.object.empty_add(type="PLAIN_AXES", location=(0, 0, 0))
            wrapper = bpy.context.active_object
            for obj in kept_objects:
                obj.select_set(True)
                bpy.context.view_layer.objects.active = wrapper
                bpy.ops.object.parent_set(type="OBJECT", keep_transform=True)
                obj.select_set(False)

            wrapper.rotation_mode = "XYZ"
            wrapper.rotation_euler = (
                math.radians(WRAPPER_ROTATION[0]),
                math.radians(WRAPPER_ROTATION[1]),
                math.radians(WRAPPER_ROTATION[2]),
            )

        # 5. EXPORT AS USDZ
        file_root = os.path.splitext(filename)[0]
        out_name = file_root + ".usdz"
        out_path = os.path.join(EXPORT_FOLDER, out_name)

        bpy.ops.object.select_all(action="SELECT")

        bpy.ops.wm.usd_export(
            filepath=out_path,
            selected_objects_only=True,
            export_materials=True,
            relative_paths=True,
        )

        print(f"  Saved to: {out_path}")

    print("----- BATCH PROCESSING COMPLETE -----")


if __name__ == "__main__":
    process_files()