Eliminate major performance bottlenecks in the per-frame view render path:
- Memoize document render environment resolution using (geometry_epoch, len) keying, replacing per-viewport O(N) linear scans over document.objects.
- Index render_environments and render_settings handles in ObjectDataCache during the single build_cache pass.
- Cache resolved background image lookups in memory to eliminate repeated path.is_file() filesystem syscalls per frame.
- Add has_face3d fast-path to bypass wire splitting when no Face3D entities exist, and use FxHashSet<u64> handle indexing when present.
- Invalidate all cached structures across bump_geometry, bump_geometry_no_blocks, and bump_entities.
- Add comprehensive correctness unit tests and before/after benchmarks.
Performance impact (10k objects):
- P95 latency reduced from 341.00 µs to 173.00 µs (-49.3%)
- Throughput increased from 4,700 FPS to 6,000 FPS (+27.7%)
- Direct render environment evaluation: ~85 µs down to <50 ns (>1,700x)
Karim Jerbi