Blender is very good at this kind of stuff 
. The importer calculates the normals (by calling a Blender function), then it adds a so called modifier, that changes the normals based on the angle of neighbouring faces. Everything that's beyond a certain threshold is rendered with a sharp corner. That works pretty well. Lego pieces have a lot of sharp corners. So for most parts the results are very good.
I've attached an example, so you can see for yourself.
The importer can be downloaded here.
. The importer calculates the normals (by calling a Blender function), then it adds a so called modifier, that changes the normals based on the angle of neighbouring faces. Everything that's beyond a certain threshold is rendered with a sharp corner. That works pretty well. Lego pieces have a lot of sharp corners. So for most parts the results are very good.I've attached an example, so you can see for yourself.
The importer can be downloaded here.