Document accurate root cause for 17 subtle pixel-diff tests#1705
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bkaradzic-microsoft merged 1 commit intoMay 21, 2026
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Triaged 17 tests previously documented as `Pixel comparison fails` / `Newly added test crashes` / `Framebuffer creation fails` / `Test fails locally on Win32 D3D11 sweep`. None of these descriptions match current behaviour. All 17 reach the renderer and produce pixel diffs (no crash, no FB-creation failure), but with consistent visible regressions: - 9 tests (160, 174, 175, 196, 197, 370, 402, 566, 587 partial) show GUI controls rendering with red/orange backgrounds where reference expects green/white -- a recurring BN GUI color regression. - 4 tests (580, 584, 587, 592) show OpenPBR analytic-lights spheres rendering saturated red where reference shows pink/white subsurface scattering or anisotropy -- spirv-cross HLSL emit gap. - 1 test (169) shows instanced billboard foliage rendering red instead of green -- vertex/instance color routing. - 1 test (179) emits extra red LineEdgesRenderer lines not in reference. - 1 test (602) Background material blur produces red splotches. - 1 test (182) has GUI slider handles red instead of green plus minor skull edge AA differences. - 1 test (256) Instanced Bones has deterministic ~3.5% px sub-pixel animation/edge-AA delta with structurally-correct render. These updated reasons help future debuggers triage rather than send them chasing the misleading `crashes` / `framebuffer creation fails` claims.
This was referenced May 18, 2026
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Per-test triage of 5 post-#1695 pixel-diff fallouts. Updates the `reason` field in `Apps/Playground/Scripts/config.json` for 3 entries to name the real BN rendering regression instead of generic "Pixel comparison fails": - idx 363 SSR2 - SSR not rendering wet floor. - idx 369 Sprites Pixel Perfect - sprite alpha-blending broken. - idx 395 soft-transparent-shadows - soft-shadow filter precision degraded. **No source changes, no test re-enables, no PNGs.** Metadata-only correction so the issue tracker reflects actionable root causes for follow-up engineering work. --- ## Landing context This PR is one of **7 splits** from the proven CI-green combined preview in **draft PR #1702** (see [#1702](#1702) for the full intended end-state and verified CI run [26044922430](https://github.com/BabylonJS/BabylonNative/actions/runs/26044922430)). > Note: the original split included an 8th PR (#1709, ES2020+ -> ES2019 syntax-repair polyfill for Chakra). It was closed in favour of investigating `@babel/standalone` properly (#1711). ### Recommended landing order **Tier 1 - parallel-reviewable, no source conflicts:** 1. #1703 - ExternalTexture C4702 build fix 2. #1704 - config.json `reason` rewrites (5 entries) 3. #1705 - config.json `reason` rewrites (17 entries) **Tier 2 - sequential, each touches `Apps/Playground/CMakeLists.txt` SCRIPTS list + `Apps/Playground/Shared/AppContext.cpp` LoadScript order; rebase the next branch after the previous merges:** 4. #1706 - File/Blob/FileReader polyfill (largest test impact: 19 re-enables) 5. #1707 - fetch polyfill 6. #1708 - DOM globals + native AbortController + Android CMake link 7. #1710 - Cubemap auto-expand polyfill (loaded after babylon.max.js) ### Reference policy reminder Reference PNGs across all 7 PRs come from Babylon.js; never re-baked by BN. Combined diff: **0 PNGs**.
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Per-test PIL-composite triage of all 17
subtle pixel-difftests. None of them are deterministic-cosmetic (no re-bakes possible - all show real visible regressions).Updates the
reasonfield inApps/Playground/Scripts/config.jsonfor 17 tests with accurate symptom descriptions, classifying into recurring root-cause clusters:No source changes, no test re-enables, no PNGs. Metadata-only correction so the issue tracker reflects actionable root causes.
Landing context
This PR is one of 7 splits from the proven CI-green combined preview in draft PR #1702 (see #1702 for the full intended end-state and verified CI run 26044922430).
Recommended landing order
Tier 1 - parallel-reviewable, no source conflicts:
reasonrewrites (5 entries)reasonrewrites (17 entries)Tier 2 - sequential, each touches
Apps/Playground/CMakeLists.txtSCRIPTS list +Apps/Playground/Shared/AppContext.cppLoadScript order; rebase the next branch after the previous merges:Reference policy reminder
Reference PNGs across all 7 PRs come from Babylon.js; never re-baked by BN. Combined diff: 0 PNGs.