CNA-VGAP-031: The real-world Khronos comparison matrix passes on one surviving renderer; GLTF ROBUST row 12 needs four

CNA snapshot 3b43bd86  ·  Known Issues › Verification gaps  ·  source links pinned to 3b43bd86

Gate C's retake matrix (Fox, DamagedHelmet, Sponza and the sparse cases against the Khronos sample renderer) is recorded passing on OPENGLES3; the two other renderers it passed on were retired, and the row needs four including a Direct3D path.

Identifier

CNA-VGAP-031

Category

Verification gap

Subsystem

Testing & evidence

Status

Open

Verified against

CNA 3b43bd86 (3b43bd8687ed46523d873f9bec4b32bd8481dcb5)

Evidence basis

Recorded by CNA: CNA's own recorded run, not repeated here

Tests touching this area

Yes: see Current tests

Affected contract

glTF import and rendering compared with the Khronos glTF-Sample-Renderer on real assets

Expected behaviour

plan_gltf.md §27.2 row 12 asks for the retake matrix to pass on at least four renderers, including one Direct3D path.

Actual behaviour at TARGET

plan_gltf.md §27.2 row 12 is open and was restated on 2026-10-13: two of the three renderers Gate C had passed on (all 14 rows, 15 cases, against each renderer's own goldens) were retired, and the harness lost its Wine route with them, so the row now needs surviving renderers (the plan names SOFTWARE, SDL_GPU and WEBGPU as candidates), and its Direct3D clause can only be met by DIRECTX9 under Wine. The remaining pass is OPENGLES3's. A further run is blocked by the harness's two external inputs (a built Khronos glTF-Sample-Renderer and a sparse glTF-Sample-Assets checkout), which the plan records as absent on its host. gltf-viewer-retake-report.json records only the OPENGLES3 run (2026-08-14, CNA commit d3c5bca6).

Source locations

• plans/plan_gltf.md — section 27.2 row 12 (restated 2026-10-13) and GLTF-459
• docs/gltf-viewer-retake-report.json — the recorded Gate C run and its pins

Evidence

Checked by reading at 3b43bd86; not executed. The pass is CNA's own recorded result.

Re-verified at c6dec91f: 644d60d9c (2026-10-14) restated row 12 after the renderer retirement; the entry's earlier count of three passing renderers is history.

Focused reproduction

No focused reproduction is known. Nothing has been invented here; the evidence above is what exists.

Current tests

The Gate C record above; no CI job reruns it.

Regression test

Gate C runs on three more surviving renderers (one of them DIRECTX9 under Wine), with byte-identical two-process captures, recorded in the report.

Blast radius

Evidence only: real-world asset parity against the Khronos renderer is established for OPENGLES3 alone.

Workaround

No workaround is known.