The 3D captcha generates new images rather than using a library, so a captcha breaker needs to use a more sophisticated approach than comparing the current capt

The 3D captcha generates new images rather than using a library, so a captcha breaker needs to use a more sophisticated approach than comparing the current captcha image to previously seen images. The difficulty of the image library captcha depends on the size of its library, while the difficulty of the 3D captcha depends on the fact that it's much easier for a computer to go from a 3D model to a 2D image rather than the other way around.