Re: Toy Story
One of the reasons these all CG features work well in 3D and a lot of live action films such as "Clash of the Titans" don't is because all CG features are created with 3d geometry and a virtual camera. To turn one into a 3d feature requires modifying the camera to be a stereo rig (essentially two cameras linked 2" apart - ie the space between most people's eyes) and then rendering the 3d geometry through each camera, essentially getting "Left Eye" and "Right Eye" renders. Then, depending on the projection format, the "eyes" are combined at projection time and synched to the glasses in the audience.
With a live action film these days, most are converted to 3d using a laborious process called "dimensionalization" which is often not very accurate or at a minimum quite limited, resulting in a sort of parallax-driven Viewmaster look. It's only when a film is shot with a stereo camera, like "Avatar" was, that the live action scene can be accurately captured for projection.