Similar to #1, If there are duplicate vertex normals, they can be combined/collapsed into one so that the data is not repeated. The struggle with this is making sure any faces that use the collapsed vertex normal are redirected to the one that was kept.
Similar to #1, If there are duplicate vertex normals, they can be combined/collapsed into one so that the data is not repeated. The struggle with this is making sure any faces that use the collapsed vertex normal are redirected to the one that was kept.