The normals at the polygon nodes (texture samples). These are the normals used for shading, and are the same as the normals that are displayed in a geometry view when you choose Normals from the Show menu (eye icon).
If you display NodeNormal in the 3D views, they may not appear to update properly when you modify the automatic discontinuity settings (in the Geometry Approximation property editor) unless you are in a shaded mode. You may also need to force an update to the ICE tree, for example, by disconnecting and then reconnecting relevant nodes.
