Complex sentence: The 2009 release of "Avatar" was shot in a 3D process that is based on how the human eye looks at an image, it was an improvement to a currently existing 3D camera system.
Split into simpler sentences: The 2009 release of "Avatar" was shot in a 3D process that is based on how the human eye looks at an image. It was an improvement to a currently existing 3D camera system.