Opening a fresh .ifc streams geometry to the GPU, then bakes the .ifcview
cache. That bake — reorder + per-chunk zstd (level 19) — ran synchronously
in SceneLoader::onStreamerFinished, which is a QueuedConnection slot on the
main thread, so it froze the UI right as the progress bar hit 100% (≈15s of
zstd for a 130 MB-geometry model).
- Move the compress + writeSidecar onto a background thread. The geometry is
already resident and the sidecar is only a cache for the next open, so the
viewport is interactive the instant streaming finishes; the write is joined
before the next write and in the destructor.
- Parallelise the per-chunk zstd across hardware_concurrency threads (compress
all chunks, then write serially to keep contiguous offsets) so the
background write also finishes quickly.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Dion Moult
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