Umbra and Culling

Target-binary evidence

Atlas indexes Load_ProcessStructLayout_UmbraGate at RVA 0x4F2A80 (321 bytes) from candidate archive_impl_r_bsp_db.h:33669-33680. The GfxWorld layout registration at 0x4D1BA0 also maps to the same candidate source, which registers Umbra gate count/data and tome size/data/reference members (source lines 32907-32923). Additional world visibility groups include GfxWorldDpvsStatic and GfxWorldDpvsDynamic. These function RVAs are target facts; structures remain candidate evidence.

Candidate serialized layout

• Candidate UmbraGate: size 0x20, alignment 4. Fields: objID uint at 0x00, Bounds at 0x04 (size 0x18), closeDistance float at 0x1C (archive_impl_r_bsp_db.h:33669-33680).
• Candidate GfxWorld Umbra members: numUmbraGates at 0x4090, gate pointer at 0x4098, umbraTomeSize at 0x40A0, byte-array umbraTomeData at 0x40A8, and tome pointer at 0x40B0 (archive_impl_r_bsp_db.h:32907-32923).
• Candidate world visibility components register dpvs and dpvsDyn at 0x3BE8 and 0x3E60; this notes the existence of static/dynamic visibility data without claiming bitset semantics (archive_impl_r_bsp_db.h:32901-32905).

Format observations

The candidate schema exposes an Umbra gate record and both an embedded tome byte array and a tome reference. Together with DPVS groups, this is evidence that world visibility/culling data is represented alongside GfxWorld. It does not reveal the Umbra tome's internal format or query runtime protocol.

Confidence and unknowns

• High: target loader symbols for UmbraGate and GfxWorld are indexed at the RVAs above.
• Medium: source mapping to the generated BSP header.
• Candidate only: listed member sizes/offsets.
• Unknown: gate ID domain, bounds coordinate convention, close-distance units, embedded-versus-external tome selection, DPVS bit ordering, cell mapping, and Umbra runtime version.

Evidence: Evidence Scope · Atlas validation · BSP/Umbra loader source.