Octree removal 2: stop building the 9 partitions nothing reads #476

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opened 2026-10-06 09:30:24 +00:00 by sky_line · 0 comments

sky_line commented

2026-10-06 09:30:24 +00:00

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These partitions are constructed, balanced, shifted and moved into, but nothing reads them under Vulkan: Terrain, Water, VoidWater, Tree, Grass, HUD, HUDParticle, Avatar, ControlAV (llviewerregion.cpp ~685-697).

Do:

Stop creating them.
Make movePartition a no-op for those object types. The per-avatar movePartition every frame (llvoavatar.cpp ~3100-3108) is the main saving.

Precondition, audit first:

LLDrawable::isVisible() falls back to group visibility (lldrawable.cpp ~1097-1101).
LLVOAvatar::updateVisibility treats "no group" as visible (llvoavatar.cpp ~5340).

Objects that lose their group must keep behaving correctly. Also check flexi isVisible and the particle sim's visible rate.

Part of #474. From the 2026-10-06 audit: the octrees are still built and maintained every frame, but almost nothing reads them. Rendering, culling, world picking, LOD, texture priority and lights all run on our own systems. These partitions are constructed, balanced, shifted and moved into, but nothing reads them under Vulkan: Terrain, Water, VoidWater, Tree, Grass, HUD, HUDParticle, Avatar, ControlAV (llviewerregion.cpp ~685-697). **Do:** - Stop creating them. - Make `movePartition` a no-op for those object types. The per-avatar `movePartition` every frame (llvoavatar.cpp ~3100-3108) is the main saving. **Precondition, audit first:** - `LLDrawable::isVisible()` falls back to group visibility (lldrawable.cpp ~1097-1101). - `LLVOAvatar::updateVisibility` treats "no group" as visible (llvoavatar.cpp ~5340). Objects that lose their group must keep behaving correctly. Also check flexi `isVisible` and the particle sim's visible rate.

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2026-10-06 09:30:24 +00:00

sky_line referenced this issue

2026-10-06 09:30:24 +00:00

Epic: remove the scene octree / spatial partitions (built every frame, almost nothing reads them) #474

sky_line added this to the Slipstream project

2026-10-06 15:04:14 +00:00

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