Per-vid outcome
Optionalerror?: stringError message when status is "failed"
OptionalsizeBytes?: numberStored size in bytes when status is "prepared"
"prepared" when the model is now available offline, "failed" when something went wrong
(see error), "skippedUnsupported" for model types that cannot be prepared for offline
use (point clouds, GLB)
Whether the browser granted persistent storage (navigator.storage.persist()). When false, the browser may evict offline data under storage pressure.
Result of Viewer3d.prepareOfflineModels