A 3D scan can look complete on screen but still fail when it reaches your slicer. Before 3D printing, the three geometry checks that matter most are real-world scale, watertight geometry, and printable wall thickness. You will also need to review orientation and supports in the slicer. This guide covers the full process, starting from a finished KIRI Engine Photo Scan export.
If you haven't captured your scan yet, start with Introduction to Photo Scan for capture basics, or Photo Scan Common Failure Reasons if your results have been coming out messy.
The Full Scan-to-Print Workflow
Import the scanned mesh into a mesh editor.
Remove unwanted geometry and repair holes.
Correct real-world scale.
Check wall thickness and printable details.
Export as STL or OBJ.
Open the model in a slicer, orient it, and generate supports.
Slice the model into G-code and send it to your printer.
Where KIRI Engine Fits Into the Workflow
Before your scan reaches a slicer, KIRI Engine can handle several parts of the preparation stage:
Photo Scan captures printable geometry directly from photos, no dedicated scanning hardware required.
Measure and Rescale correct real-world dimensions before export, addressing the scale mismatch that catches most scanned models off guard in a slicer.
Dynamic Decimation can reduce mesh density when a scan is too heavy for smooth slicing or sharing. Use it only as much as needed, since aggressive decimation can remove fine printable detail.
STL and OBJ export work directly with Cura, PrusaSlicer, and most other slicing software.
The rest of this guide covers what still needs to happen before and after those steps.
What You're Starting From
A raw Photo Scan export is a dense mesh reconstructed from overlapping photos, usually with a baked texture. For most single-material FDM or resin prints, texture data does not affect the printed geometry; mesh solidity, scale, and printable feature size matter more. Unlike Photo Scan's Blender or game-engine workflows, you don't need retopology, PBR materials, or UV work here. What you need is a mesh that's watertight, correctly scaled, and thick enough for your printer to reproduce reliably.
Fixing Scale Before It Reaches the Slicer
This is the step most scanned models get wrong, and it's usually not obvious until you've already opened the file in your slicer and the dimensions are off.
Photogrammetry reconstructs shape from photos, not absolute real-world size. Without a reference measurement, a scan can come out at a plausible but incorrect scale. If you're using a third-party tool to guess and manually adjust dimensions after the fact, that's extra round-trips you don't need.
KIRI Engine's Measuring and Scaling tool addresses this directly, before export:
Measure. After your scan finishes processing, select the Measure option and pick two points on the model. KIRI Engine returns an AI-estimated distance between them.
Rescale. That initial measurement is an estimate, not a guarantee. Tap Rescale, enter the actual real-world measurement between those same two points (measured with calipers, a ruler, or any known reference), and the model snaps to the correct scale.
Export. Export the corrected model as STL or OBJ, then open it in your slicer.
This works best when you pick two points with a clear, easy-to-measure real-world distance, like the width of a base or the length of a straight edge, rather than two points on a curved or ambiguous surface.
Checking for a Watertight Mesh
Slicers need a closed, manifold surface to generate proper infill and shell structure. Holes, most commonly on the bottom of the object (if you didn't scan that angle) or wherever photo coverage was thin, will cause slicing errors or unpredictable infill behavior.
If you scanned with the turntable method or captured the bottom separately, you're likely to have fewer holes to deal with here.
For remaining holes, import the mesh into a modeling tool (Blender, Meshmixer, or Tinkercad all work) and use fill or patch tools to close the gaps. Some slicers can detect or repair simple mesh errors, but larger holes and missing surfaces are better fixed in Blender or another mesh-editing tool.
Wall Thickness and Detail Limits
A scan can capture detail your printer physically can't reproduce. Thin protrusions, fine surface texture, or narrow gaps that photogrammetry recorded accurately may not survive slicing at low resolution, or may need supports to print at all.
Check your slicer's minimum wall thickness recommendation for your printer and material (this varies by machine and filament, so check your printer's documentation) against the thinnest features in your model before printing. If a feature is thinner than your printer can reliably produce, you have two options: scale the whole model up, or manually thicken that specific area in a modeling tool before export.
Supports and Orientation
Once your model is scaled and watertight, orientation matters as much as the geometry itself. A scan captured in one orientation isn't necessarily the best orientation for printing.
Look for a stable base with enough flat contact area to avoid needing extensive supports. If the object has overhangs (a common issue with organic or irregular scanned shapes), your slicer will flag where supports are needed. Most slicers generate these automatically; you generally only need to intervene if the auto-generated supports are excessive or landing in visually sensitive areas.
Exporting and Slicing
Export your repaired, correctly scaled mesh as STL or OBJ. Both formats are supported by Cura, PrusaSlicer, and most other slicers. Because STL does not store an explicit unit definition, verify the model dimensions once more after import before generating G-code. Then apply your printer and material profile, review orientation and supports, and slice the model.
Common Problems
Model prints at the wrong size despite looking correct on screen. This is almost always a scale issue that was never corrected before export. Use the Measure and Rescale steps above before exporting, not after.
Slicer reports a non-manifold or non-watertight mesh. There's a hole somewhere in the geometry, even if it's not visually obvious. Check the bottom of the object and any areas with thin photo coverage first.
Thin details disappear or break off after printing. The feature was likely thinner than your printer's minimum reliable wall thickness. Either scale the model up or thicken that specific area before export.
Model needs heavy editing before it's print-ready. If you're doing more than basic hole repair and scale correction, such as significant reshaping or combining multiple scans, you may be better served by the full cleanup workflow in Photogrammetry to Blender: Cleanup, Retopo, and Export before bringing the result back here for printing prep.
Frequently Asked Questions
Do I need Pro to print a scanned model? No. KIRI Engine Basic is enough for most scan-to-print workflows. It includes Photo Scan, STL and OBJ export, Dynamic Decimation, and unlimited watermark-free exports.
Why does my scan look correct in the app but wrong once I open it in a slicer? Most often, this is a scale issue, since photogrammetry reconstructs shape without inherently knowing absolute size. Use the Measure and Rescale tool before export rather than adjusting dimensions manually after the fact.
Can I 3D print directly from a raw Photo Scan export, with no repair at all? Sometimes, if the object was fully covered during capture and has no holes. In practice, most scans need at least a scale check and a quick look for holes on the underside before they're reliably print-ready.
Do I need Quad-Mesh Retopology or PBR Material Generation for printing? No. Those Pro features are built for Blender and game-engine workflows where clean topology and material maps matter. For printing, mesh solidity and scale are what matter, not topology or texture.
What file format should I export for 3D printing? STL is widely supported across most FDM and resin slicers, but it stores geometry without explicit unit, color, or material information. OBJ can be useful when color or material data needs to be preserved. Whichever format you choose, verify the model dimensions after import.
Related Reading
Capture basics: Introduction to Photo Scan
Troubleshooting a failed scan: Photo Scan Common Failure Reasons
Full mesh cleanup for complex edits: Photogrammetry to Blender: Cleanup, Retopo, and Export
What's included in Basic vs Pro: KIRI Engine Basic vs Pro
