# W-078 Status

status: in_progress  
task: 轻量化预算和导出策略

`protocol/budget.ts` now validates explicit integer budgets for triangles,
vertices, index bytes, material slots, texture bytes and estimated GPU bytes.
`evaluateLightweightBudget` returns every violation with limit, actual value and
excess while leaving the measured usage unchanged. Browser E2E covers a mixed
triangle/GPU over-budget report.

`aggregateLightweightUsage` and `evaluateLightweightBudgets` now produce
deterministic project, collection, object and LOD scopes. Project usage sums
each source object once; collection membership is reported per collection and
LOD usage is kept separate so generated levels are not double-counted. Browser
E2E covers all four scope reports.

`analyzeGLBExport` now runs before the UI export action and returns structured
warnings/errors for summary-only or missing geometry, unevaluated modifiers,
external/packed images, linked material inputs and unavailable skin remapping.
When no blocking condition is present, the local exporter writes a standards-
shaped GLB 2.0 binary containing hierarchy, mesh positions/normals/UVs/colors,
material groups, PBR material factors and shape-key morph targets. Blender
shape-key positions are converted to glTF deltas in the Z-up to Three.js/glTF
basis conversion. The top-bar action downloads this local binary; browser E2E
checks the GLB header and a non-zero morph delta.

`exportGLB` now accepts caller-provided local asset buffers, embeds each image
as a GLB buffer view, and connects it to exported PBR materials. It exports
`JOINTS_0`/`WEIGHTS_0`, bone nodes, inverse bind matrices and supported object
or bone animation channels for a resolved armature binding. The local test
worker parses the emitted GLB JSON again; browser E2E embeds a real local PNG
and verifies its byte length/signature, skin joints, MAT4 inverse-bind accessor,
animation channels and skin attributes without a network fetch.

The native reader now extracts the exact bytes of both legacy and list-based
Blender packed images through the local asset request ABI; the packed fixture
checks PNG signature, MIME and byte length without a network request. The GLB
worker strictly parses the emitted JSON/BIN chunks and compares mesh
attributes, embedded image byte counts/MIME, skin joints/inverse-bind MAT4s,
morph targets and grouped animation paths against the source SceneIR. The
browser round-trip test has no semantic mismatches. Blender-side unsupported
features remain explicit export warnings.