From 3D Scan to Printable STL: A Practical Workflow

Whether it came from a structured-light scanner, a LiDAR iPhone app, or a photogrammetry pipeline, a fresh 3D scan is rarely printable as-is: it is huge, full of holes and floating debris, and usually saved as a PLY file that your slicer may not accept. Here is the path from raw scan to clean STL.

Step 1: If you have a point cloud, mesh it first

Some scanning tools export a point cloud - millions of points, no surfaces. A printer needs surfaces. In MeshLab, run Surface Reconstruction (Screened Poisson) to turn points into a watertight mesh; CloudCompare's Poisson reconstruction does the same. If your scanner already exported a mesh with faces, skip ahead.

Step 2: Clean up the mesh

• Delete floating fragments and scan-table geometry (MeshLab: select connected components, keep the largest)
• Close holes so the mesh is watertight - slicers can often repair small gaps, but big ones cause failed prints
• Flatten the base if the object should sit on the print bed

Step 3: Decimate to a sane triangle count

Scan meshes are uniformly dense - flat cheek and sharp ear get the same tiny triangles. Quadric Edge Collapse Decimation in MeshLab typically cuts 60-80% of triangles with no visible change on a print. Under a million triangles is a comfortable target for slicing; our guide on reducing STL file size covers this in more depth.

Step 4: Convert the PLY to STL

With the mesh clean, the last step is format: drop the PLY into our free PLY to STL converter and download a compact binary STL. The conversion runs locally in your browser - scan data never leaves your machine. One heads-up: STL cannot store your scan's vertex colors, which is expected for single-material printing.