How background rendering works
Updated Jul 29, 2026 · 1 min read
Thumbnails render in a pool of background workers sized to your machine automatically. No tuning required.
Thumbnail rendering runs in a pool of background workers so a big scan can use several CPU cores at once. The pool sizes itself to your machine (one worker per CPU core, keeping one core free so the app and your system stay responsive), spins workers up only when there's rendering to do, and winds them back down once they've been idle. Memory is sized to your machine too: very mesh-dense files are processed a couple at a time within strict memory bounds, so a folder of 100 MB models can't blow past your RAM no matter how many cores you have.
There's nothing to tune. On a fresh library the pool works through the backlog at full tilt; once the thumbnails are built, rendering goes quiet and only wakes for new or changed files.
Rendering is designed to run in the background: you can keep browsing and using the viewer while the pool works through the queue.
Skipping folders you don't want scanned
The scanning knob that does exist: the Scanning section in Settings takes a list of excluded names, so folders or files matching those patterns are left out of scans entirely, handy for backup dumps or work-in-progress folders you don't want in the library. See What Meshory indexes for the full picture: supported formats, folder exclusions, and index-only patterns.