Expensive half of GSplats node loading: fetch the splat arrays via
the loader, process them, and commit geometry into the placeholder
(found by name in the root group). Safe to call after initial scene
load returns (lazy lod_group levels) — it checks isDatasetLive()
before committing so a load still in flight when the user switches
datasets never writes into a disposed/replaced scene.
Expensive half of GSplats node loading: fetch the splat arrays via the loader, process them, and commit geometry into the placeholder (found by name in the root group). Safe to call after initial scene load returns (lazy lod_group levels) — it checks
isDatasetLive()before committing so a load still in flight when the user switches datasets never writes into a disposed/replaced scene.