nx_shellclose.nx

nx_shellclose.nx -- CLOSE a reconstructed open sheet into a WATERTIGHT SOLID by offsetting it along its own normals and stitching the rim. WHY: a single-view reconstruction is an open sheet. nx_meshthick correctly returns -1 on it -- an open surface has no opposing face, so wall thickness is UNDEFINED. Every downstream twin measurement that matters for flip analysis (min wall, underbuilt flags) therefore cannot run on reconstructed geometry at all. Offsetting the sheet gives a closed body those organs CAN measure. ⚠HONEST SCOPE, and it must travel with every number this produces: the back surface is SYNTHESISED, not observed. This is a SHELL of assumed thickness, not a two-sided capture. It makes the reconstruction measurable and watertight; it does NOT make the far side real. A true solid needs views from both sides. license_tier: ORIGINAL