Omar SobhandClaude Opus 5
4358964c05
55 of 85 role skill bindings pointed at skills that were never authored,
so 10 of 11 team templates bound a smaller context bundle than their role
prompts assumed. Three roles bound nothing at all (gpu.bench_engineer,
threejs.shader_author, threejs.perf_engineer) while their prompts described
procedures they had no way to read.
The loader comment at team_template_loader.rs:167 already diagnosed this —
snake_case slugs in TOML against kebab-case skill files — and it was
half-fixed: the kebab names were corrected, the snake_case ones left.
It was invisible because both existing tests assert authored ⊆ referenced
(30/30, green) and the second explicitly declines to check the other
direction. So the failing half was the half nobody asserted.
Resolved every name by one of three explicit choices:
- 23 skills authored where the role genuinely needed the procedure
(gpu, threejs, research, analysis, frontend, mobile, backend, platform)
- renames onto authored skills where one existed in substance, including
the four-near-duplicate cases that collapse onto one real skill
- 22 aspirational references deleted — a binding an agent cannot read is
a promise, not a capability
Two tests now hold it. The unit test checks referenced ⊆ authored against
the files. The new integration test runs both loaders in boot order and
asserts the bindings survive the trip through the database, which is a
different question: resolution goes through skills_catalog rows, so a skill
file that exists but fails to ingest still leaves the role empty.
Negative controls: the unit test failed naming all 55; the integration test
fails naming the exact role when one name is reverted.
threejs.shader_author and .perf_engineer gained a second and third skill
after the collapse — pin_in_context pins idx < 2, so a role left with one
skill silently pins less than the policy intends.
Co-Authored-By: Claude Opus 5 <[email protected]>
60 lines
2.4 KiB
Markdown
60 lines
2.4 KiB
Markdown
---
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name: scene-graph-planning
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description: Structuring a three.js scene graph so transforms, culling and disposal stay tractable as it grows.
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when_to_use: You are the scene designer laying out a three.js scene before objects are built.
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tags: [threejs, architecture]
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---
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# The graph decides what is cheap later
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Scene-graph shape determines transform cost, culling effectiveness and whether
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teardown is possible. All three are painful to change once content exists.
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## Group by what moves together, not by what looks similar
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Every `Object3D` with a dirty transform forces a matrix recomputation down its
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subtree. A graph grouped by *material* or by *asset file* means moving one
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object dirties unrelated branches. Grouped by motion, a static branch stays
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clean for the life of the scene.
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```
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world
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├── static ← matrixAutoUpdate = false, set once
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│ ├── terrain
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│ └── props
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└── dynamic
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├── player
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└── vehicles
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```
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`matrixAutoUpdate = false` on the static branch removes it from per-frame
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traversal entirely. This is usually the single largest CPU win in a scene with
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many objects, and it costs one line.
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## Frustum culling works on bounding volumes, not intent
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Culling is per-`Mesh` against its bounding sphere. Two consequences:
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- **A merged mesh cannot be partially culled.** Merging 500 props into one draw
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call also means all 500 are drawn whenever any part is on screen. Merge by
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spatial locality, not by material alone.
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- **A wrong bounding volume silently misbehaves.** After deforming geometry,
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call `computeBoundingSphere()`, or the object pops out of view when its
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stale sphere leaves the frustum.
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## Plan disposal with the graph
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WebGL resources are not garbage collected. Every geometry, material and texture
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needs an explicit `dispose()`. If ownership is not planned into the graph, a
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scene swap leaks GPU memory until the tab dies — see `threejs-perf-and-teardown`.
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The rule that makes this tractable: **one owner per resource**, recorded where
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it is created. A texture shared by twenty materials is disposed once, by the
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thing that loaded it, not by whichever material is torn down first.
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## Depth is not free
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Deep hierarchies cost traversal on every frame. Prefer a shallow graph with
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explicit groups over mirroring an asset's exported nesting, which is usually an
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artefact of how it was modelled rather than how it behaves.
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