OBJ and PLY 3D model thumbnails in Windows Explorer

What you see

• The mesh is drawn flat-shaded from a consistent three-quarter angle on a transparent background, the same way for every file in the folder.
• Dense scans are streamed: millions of triangles are drawn as the file is read rather than loaded into memory first.
• Quick preview (press Space) shows the same rendering at full size.

Limits

• The thumbnail shows the shape as plain shaded geometry from one fixed angle.
• Geometry is read defensively, because the file may come from anyone: non-finite values are dropped, and the drawing work and memory use are capped.
• In OneDrive and other synced folders, files stored on the PC get thumbnails as anywhere else. Online-only files are left to the cloud app, since nothing is downloaded just to draw a thumbnail.

Extensions this covers

See every format SageThumbs 2K supports or browse all format guides.

Thumbnails not showing?

• Windows caches thumbnails, and a file it failed on once stays failed. In SageThumbs, Settings ▸ Advanced ▸ Rebuild thumbnail cache clears the cache and restarts Explorer.
• Make sure File Explorer's "Always show icons, never thumbnails" option is off, and that the format is ticked in SageThumbs Settings ▸ File types.
• Run st2k doctor in a terminal. It only reads, checks the whole chain, and prints a fix under anything that is wrong.

Related guides

• STL3D-print models, rendered as shaded thumbnails.
• G-code and 3MFSliced prints and 3MF projects, from the picture the slicer saved.
• Blender .blendBlender scenes and their numbered backup files.
• Fusion 360 .f3dFusion 360 archives, from the preview packed inside.