Is it possible to access the "exact" facet body via nx open? The faceted body collectors via nxopen and UF only seem to contain geometry related to lightweight represenation as changing facet settings does nothing to change the number of facets.
I don't know what you mean by the "exact" facet body.
The NX/Open functions for reading facet data will just give you the facets that are present in an existing facetted body. If you want more (finer) facets, you have to exert control over the process that generated the facetted body. For example, When you generate a facetted body from a normal "curvy" solid body, you can adjust various parameters, such as distance and angle tolerances and facet size.
If you want to generate facets from a solid body, call NXOpen.UF.UFFacet.FacetSolid. It gives you quite a bit of control over how many facets are generated.