nx_csg.nx

nx_csg.nx -- CSG solid -> watertight mesh via marching tetrahedra over an SDF. Samples a two-primitive boolean field (nx_sdf) on a grid, splits every cube into 6 tetrahedra (Kuhn subdivision along the 0-7 diagonal -> shared faces split identically, no cracks), and emits the zero-isosurface. Edge crossings are computed in a CANONICAL endpoint order so a grid edge shared by two tets yields the IDENTICAL point (watertight, the same fix the slicer needed). Triangle winding is forced outward via an inside-reference test. Output is a pipeline- native Q14-mm NxMesh -> flows to nx_stl_write_mesh -> slicer, like every other solid. Robust by construction: SDF booleans never fail the way B-rep does. license_tier: ORIGINAL