How this 3MF preflight works
The checker resolves supported 3MF build items, component references, transforms and repeated objects in your browser, then measures that final build in millimetres. It does not substitute a raw resource or first mesh for the placed print arrangement.
Wall thickness is sampled at up to 2,000 triangle locations, so it can miss narrow features. A clean result cannot guarantee a physical print: material, nozzle, orientation, supports, calibration and slicer settings still matter.
Example workflow
A build with open edges, thin sampled areas and an oversized resolved arrangement should be repaired first where that is safe, checked again, then reviewed in the Dimensions and Wall Thickness Checkers. Do not solve a mesh defect by scaling it, and do not convert to STL unless a geometry-only copy is genuinely needed.
3MF preflight FAQ
Does this check every object placed in a 3MF build?
It resolves supported placed build geometry, including repeated objects and transforms, before analysis.
Why can a declared unit still need review?
A unit declaration gives useful scale context, but it cannot prove the source export used the intended physical size.
Can this guarantee that a 3MF will print?
No. It is a pre-slicing screen, not a replacement for the intended printer profile and layer preview.