STLAR: STL 3MF OBJ AR Viewer

RandoTechNerd

About this app

Stop guessing whether a model will fit. STLAR puts any STL, 3MF, or OBJ into the "REAL" world at its true printed size, through your phone's camera, so you can see the thing before you spend four hours printing it.

Find a model. Open it in STLAR. Tap a surface. It lands at 1:1 — walk around it, crouch down, hold your hand next to it, then decide whether it's worth the filament.


WHAT IT DOES

• Opens STL, 3MF, OBJ, GLB and glTF files, straight from Downloads, Drive, or the share sheet in your slicer
• Shows the exact bounding box in millimetres, volume in cm³, triangle count and part count — the same figures your slicer would quote
• Places the model in AR at true scale, or at 50%, 200%, or anything in between
• Draws a live measurement box around it, updating as you resize
• Locks the model where you drop it, so a stray finger can't nudge it
• Works in portrait and landscape


MATERIALS AND FINISHES

Sixteen materials with real metallic and roughness values: PLA, PETG, ABS/ASA, TPU, Nylon, Resin, PEEK/Ultem and carbon fibre, plus machined aluminium, stainless steel, titanium, brass and copper, and clay, acrylic and wood.

Each carries its own ranked finishes — pick aluminium and you get mill, brushed, polished, bead blast and the anodising colours. There's also a custom colour picker with a hex field, plus transparency, gloss and reflectiveness sliders.


MULTICOLOUR 3MF

STLAR reads colour three ways — the core 3MF specification, Bambu and Orca project settings, and PrusaSlicer volume data — so a two-tone nametag arrives as a two-tone nametag, with its parts still separate.


SHARE WHAT YOU SEE

Capture the AR view with its measurements and send it to a customer, a client, or your group chat.


EVERYTHING RUNS ON YOUR PHONE

No upload. No account. No server. The whole conversion happens on the device, which means STLAR works in a workshop with no signal, on a plane, or somewhere your files are never allowed to leave the building.


REQUIREMENTS

AR needs an ARCore-supported device and Google Play Services for AR. If your device doesn't support AR, the 3D viewer, measurements and materials all still work.


A NOTE ON ACCURACY

Measurements come from your file's own geometry and are accurate to it. AR placement depends on your device's tracking, so treat the on-screen box as a design aid rather than a certified instrument — don't machine to them without checking.


Built by RandoTechNerd.
Questions, bugs and feature requests: [e-mail]

What’s new

Fixed

• Full screen had no way back out on some phones: the exit button sat underneath the status bar and could not be tapped. It works now, and the back gesture also leaves full screen.
• On phones and foldables with a camera cutout, controls could sit underneath it in landscape.