I read through the papers and my impression was that the biggest gains were from quantised coordinates and dynamic LOD for small patches instead of the entire mesh.
The logic behind nanite as I understood it was to keep the mesh accuracy at roughly 1 pixel precision. So for example, a low detail mesh can be used with coordinates rounded to just 10 bits (or whatever) if the resulting error is only about half a pixel when perspective projected onto the screen.
I vaguely remember the quantisation pulling double duty: not only does it reduce the data storage size it also helps the LOD generation because it snaps vertices to the same locations in space. The duplicates can then be eliminated.
The logic behind nanite as I understood it was to keep the mesh accuracy at roughly 1 pixel precision. So for example, a low detail mesh can be used with coordinates rounded to just 10 bits (or whatever) if the resulting error is only about half a pixel when perspective projected onto the screen.
I vaguely remember the quantisation pulling double duty: not only does it reduce the data storage size it also helps the LOD generation because it snaps vertices to the same locations in space. The duplicates can then be eliminated.