I have to admit, even with 25+ years experience with computer graphics, on first viewing I thought The Lego Movie was mostly done with stop action photography.
I figured maybe 80% physical and 20% virtual. Turns out it was closer to 99% CGI with some real legos thrown in for good measure. Other than the live action scenes, I couldn’t tell you where the real legos sat.
There were some things, like the water, explosions and more, that looked way too procedural to be done by hand. But still the rendering, shading and animation were so close to perfect, so physically correct down to sub-surface scattering and extreme depth of field, that it was almost impossible to tell.
Amazing job. And especially impressive given how well they could tell the story without relying on the usual tricks of animation and CG, staying true to only what real legos can do.
The real tip-off about the CGI was in the lighting, which allowed for certain legos to emit light or light to come from no actual source. That would be pretty hard to do in reality without a really complex effects pipeline on top.
Here’s a longer video that explains how it was done: