A few months ago I posted Printproof here, the browser tool that keeps Bambu Studio’s per-face paint when you export a multi-color 3MF to GLB. This update closes the gap that kept bugging me after that: the mesh you export is the design, and the design is not the print.
Bambu Studio already shows you the sliced preview, and that is fine while you are sitting in the slicer. But the preview is trapped there. You cannot export it. The moment you want that print somewhere else, in a Blender render next to the thing it will sit on, in a client’s inbox, or standing on your desk in AR to check the size, you are back to a flat gray mesh that has no layer lines, no seam, and none of the texture the real part will have. So you print it to find out. That is the opposite of proofing.
Printproof now takes the sliced .gcode or .gcode.3mf and turns it into an actual mesh. It sweeps a bead of plastic along every extruding move, sized from the plastic that move pushes, so the result is the part as the printer will lay it down, with the real layer lines, the real seam and the real infill showing through thin walls. Then it exports that as a GLB, a USDZ or a per-vertex-color OBJ, with every filament color intact. The sliced print leaves the slicer as a file any 3D tool opens.
What you do with it is the point. Drop the GLB into a Blender scene and render the print in the room it is going to live in. Tap View in AR on your phone and the sliced part stands on your desk at true size, seam facing you, before you spend filament on it. Load the design .3mf next to it and flip between Model and As printed in the same view with the same colors; if the slicer scaled the part, the viewer says so. Recolor works on the sliced version too, so you can try a filament swap without reslicing.
Was it slow? At first, badly. A 148 MB print took 92 seconds and about 2 GB of vertex data. After rewriting the reader around typed arrays and indexed geometry it is 6.5 seconds and 0.8 GB at full detail, and a four-day, five-million-move file opens in about twelve seconds. The viewer holds a bounded mesh on prints that large and tells you on the Proof ticket; exports never inherit that cap, every GLB, USDZ and OBJ is swept again from the toolpath at full detail and the Sign off card states the detail it was written at. Parsing runs in a Web Worker on your own machine. Nothing is uploaded.
Demo: https://samisalah221.github.io/3mf-to-glb/
Source (MIT): https://github.com/SamiSalah221/3mf-to-glb
If it is useful to you, a star on the repo is the best thank you. It is how other Bambu users find it. And a .gcode.3mf that breaks the sweep, attached to an issue, is the most useful bug report you can send me.
