Download OBJ previews of products from Bad Dragon

dragon_download.py

from typing import List, Iterator

import os
import urllib.request
import json
from dataclasses import dataclass
import argparse

PRODUCT_URL = "https://bad-dragon.com/api/products"
SAVE_DIR = "models"


@dataclass
class DownloadableProduct:
    name: str

    preview_object_url: str
    preview_texture_map_url: str
    preview_normal_map_url: str


def load_products() -> List[dict]:
    with urllib.request.urlopen(PRODUCT_URL) as f:
        return json.load(f)


def process_products(products: List[dict]) -> Iterator[DownloadableProduct]:
    for product in products:
        name = product.get("sku")
        preview_object_url = product.get("previewObjModel", {}).get("url")
        preview_texture_map_url = product.get("previewTextureMap", {}).get("url")
        preview_normal_map_url = product.get("previewNormalMap", {}).get("url")

        if (
            not name
            or not preview_object_url
            or not preview_texture_map_url
            or not preview_normal_map_url
        ):
            continue

        yield DownloadableProduct(
            name, preview_object_url, preview_texture_map_url, preview_normal_map_url
        )


def download_file(url: str, path: str) -> None:
    if os.path.exists(path):
        print("Already downloaded {path}".format(path=path))
        return

    print("Downloading {path}".format(path=path))
    urllib.request.urlretrieve(url, path)


def download_product(
    product: DownloadableProduct, save_dir: str, include_maps: bool = False
) -> None:
    download_file(
        product.preview_object_url,
        os.path.join(save_dir, "{name}.obj".format(name=product.name)),
    )

    if include_maps:
        download_file(
            product.preview_texture_map_url,
            os.path.join(save_dir, "{name}_texture_map.png".format(name=product.name)),
        )
        download_file(
            product.preview_normal_map_url,
            os.path.join(save_dir, "{name}_normal_map.png".format(name=product.name)),
        )


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Download Bad Dragon preview objects.")
    parser.add_argument(
        "--maps", help="include texture and normal maps", action="store_true"
    )
    parser.add_argument("dir", help="Path to save models", nargs="?", default=SAVE_DIR)

    args = parser.parse_args()

    if not os.path.exists(args.dir):
        os.mkdir(args.dir)

    print("Saving objects to {dir}".format(dir=args.dir))

    products = load_products()
    for product in process_products(products):
        download_product(product, args.dir, args.maps)

I was getting 403 Forbidden errors when downloading the maps, which I assumed were related to the User Agent, since I could open the URLs and download the maps in my normal browser.

I changed two lines in the download_file function, so that I could add my own user agent to the request:

def download_file(url: str, path: str) -> None:
    if os.path.exists(path):
        print("Already downloaded {path}".format(path=path))
        return

    print(f"Downloading {path}")
    opener = urllib.request.URLopener()
    opener.addheader('User-Agent', 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:138.0) Gecko/20100101 Firefox/138.0')

    opener.retrieve(url, path)

Now everything works as expected when using --maps :)