As spotlighted by the folks over on PHPClasses.org, there's a developer, László Zsidi, who has contributed several packages to the repository - including some that work to create 3D images with just the built-in functions PHP provides.
He has developed several pure PHP components that implement impressive 3D animated graphics, like a 3D objects rendering engine, emulate a waving flag or the reflex of an image near a lake. The generated frames are combined into a single animated GIF with another pure PHP component also written by László. All these components were nominated to the PHP Programming Innovation Award for the evident creativity, demonstrating that PHP can be used for non-trivial software applications.
Some of the libraries in the listing include: