A YDD file acts like a container. A single weapon model might be a collection of twenty sub-meshes (barrel, scope, magazine, stock). Older converters would flatten this into a single, unmanageable chunk of geometry. Newer solutions and plugins—specifically those being developed for **Blender

If you meant to request a tool or compare existing ones, you could say:

YDD files (Yamaha Dictionary Drawables? No—Rockstar’s proprietary "Drawable Dictionary" format) contain the visual assets of the game world: characters, vehicles, weapons, and environmental props. Yet, for years, the bridge between this proprietary format and the universal, industry-standard OBJ format has been rickety at best.