Go and see The Lego Movie. Drop whatever you are doing and go and see The Lego Movie. Right now. Immediately. Get in a car or on a bus or run, don’t walk, to your nearest cinema to go and see The Lego Movie now. Do it. Vamanos.
The total production time on the film was over four years. By the time the final shots were rendered, some of the earlier ones had to be redone because they didn't match anymore. Also, the software used to create them had become more advanced (and hence more detail was possible).