ReadonlydeletedSet of input face hashes that were deleted by the operation.
ReadonlygeneratedMap from input face hash → newly generated face hashes (e.g., fillet surfaces).
ReadonlymodifiedMap from input face hash → result face hashes it was modified into.
Shape evolution record — tracks how input faces map to result faces through a kernel operation (boolean, transform, fillet, etc.).
For each input face hash,
modifiedcontains the result face hashes it evolved into.generatedcontains hashes of newly created faces (e.g., fillet rounds).deletedlists hashes of faces that were removed entirely.