fix(render): retain surfaceless particle metadata

Preserve a successfully decoded GfxObj ParticleGfxInfo when SurfaceId is zero and condition only texture acquisition. Missing/no-Gfx descriptors retain Default behavior; material, additive, routing, and untextured drawing remain unchanged.

Add a production-path GfxObj-backed synthetic no-surface pin with distinct authored/AABB centers, non-unit size, nonidentity orientation, object/particle merge order, visual center, and unassigned texture-slot assertions. Correct the synthetic-DAT evidence wording and advance only the S4-c3a ledger row.

Final F2 source audit found no defect: preparation holds reconstruction inputs only; Append reserves once; false and exception roll back the exact tail once; first-use rejection remains registered; accepted tokens stay stable; independent 3000-entry caps preserve row-2 immediate duplicates; flush/end/abort/next-preparation cleanup converges; retained capacity/bytes remain bounded; warmed production paths remain 0 B.

Gates: no-surface target 1/1; unchanged section 19 baseline 95/95; AP boundary/count 1/1; real allocations 2/2 at 0 B; shader/manifest 32/32; Release solution 0 warnings/0 errors; diff-check pass. No graphical client.

Mutation: restoring eea5793d2's SurfaceId-zero-to-Default ternary first failed CellTurn_GfxObjBillboardWithoutSurfaceRetainsAuthoredSortCenterAndUntexturedFallback at the authored-distance assertion, expected 40 actual 100.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

docs/plans/2026-09-01-campaign-overhaul-world-solidity.md

@@ -678,7 +678,7 @@ Update immediately when a slice changes state. Chat is not the ledger.
 | S4-c2 stop | **STOPPED UNLANDED 2026-09-04** — lead final-round contract `ac74fbd84`; evidence commit `c4cbc1d0d` in `s4-c2-impl` on `cc8e5677a`/`048d5b12f`; campaign renderer remains S4-c1 `766f9e749` | G3/G4 UNPASSED | Both sequential final lenses FAIL, so the required repair is the forbidden THIRD round. EnvCell transparent/ClipMap batches still draw in the opaque pass before FIFO submission and then redraw; CLIP/detail-immediate replay binds StraightAlpha with depth-write off rather than retail clip-test/depth-writing state; tests omit the preceding opaque call and pipeline descriptors. Source-owned EnvCell lists are unbounded under queue rejection, the claimed scan/filter/RHI 0-B evidence bypasses those paths, and AP-238/AP-240/result truth is false. Full file:line and gate record: S4 packet §13. No chunk cherry-pick, graphical gate, or soak. Resume only on explicit owner process change. |
 | S4-c2 owner repair | **STOPPED UNLANDED 2026-09-04** — owner-authorized implementation `a094bf2b7` is clean in `s4-c2-impl`; packet §15 is the review record | G3/G4 UNPASSED | The repaired renderer behavior passed the retail lens: exact whole-leaf pass membership, `0x08`/`0x09` CLIP, row-3 override, blend/reference/depth state, sentinel separation, detail state, rollback, allocation, AP-238/AP-240. The lens still returned FAIL: commit body omitted the required per-mutation first failures, packet mutation 5 names the wrong first assertion/address, and four source/test comments are stale. Sequential production lens therefore did not run. Correcting those items is a post-review fourth repair, which §14 does not authorize. Nothing landed or graphically gated; resume only by explicit owner process decision. |
 | S4-c2 attempts 1–5 | **ATTEMPT 1/5 CONSUMED; ATTEMPT 2/5 PASSED AND LANDED 2026-09-04** — reviewed implementation `daaeab0ba`; campaign stack `89f1e2676` → `9ccb61a8e` → `0aa166aa0` → `252886e84`; packet §17 | G3/G4 UNPASSED | Sequential retail/evidence then production/gate-honesty PASS. Fresh: Release 0W/0E; shader 32/32; affected 37/37; real allocation 2/2 at 0 B; production 239/239. Official no-retry hermetic 16,734/1: sole unchanged global `Console.Out` capture race, exact theory 2/2 isolated. InstalledDat 255/10 documented/1. Validation routes `selfgate-20260904-115818-s4c2-landed-route` and `selfgate-20260904-120025-s4c2-landed-g3b` PASS provisional. First soak failed on known #461/#462; retry and S4-c1 control both 9/9 graceful; stationary averages CPU p95 −0.01 ms, GPU p95 +0.16 ms, alloc p50 +1.2 KiB, update p95 −0.12 ms. Three attempts remain unused. |
-| S4-c3a | **ATTEMPT 3 RETAIL FAIL; §19 FIX ROUND 1 IMPLEMENTED — REVIEW PENDING.** Candidate `44e2bc227b` used the billboard's rendered/AABB-derived center instead of GfxObj's authored sort center, reserved prepared payload before queue visibility, did not bound the new retained preparation list, and misstated static-record ordering. The §19 repair now keeps authored and visual centers distinct, applies scale/orientation to the authored CYpt point, reserves and exactly rolls back at Append, caps preparation at 3,000 CLIP + 3,000 ALPHA, preserves immediate duplicates, and corrects the comment. Return gates: Release 0W/0E; focused 95/95; register pin 1/1; real allocation 2/2 at 0 B; shader/manifest 32/32; hermetic 16,751/16,751; InstalledDat 385 pass / 10 expected fail / 1 skip with the exact documented set; eight discriminating mutations recorded in packet §19.5. | G3/G4 UNPASSED | Retail re-review F1/paired bytes/F3 and unchanged S4-c2 behavior, then production/gate-honesty review of the full c3a stack with special attention to F2. One bounded fix round remains after §19; a further finding stops the chunk. c3b remains locked. |
+| S4-c3a | **§19 RETAIL RE-REVIEW FAIL; §20 FINAL FIX ROUND 2 IMPLEMENTED — FINAL REVIEW PENDING.** Candidate `eea5793d2` replaced every successfully decoded zero-Surface GfxObj with `ParticleGfxInfo.Default`, discarding authored SortCenter, AABB visual center, axes, and degrade mode. The §20 repair preserves decoded metadata and conditions only texture acquisition; a production-path synthetic no-Surface GfxObj proves distance² 40, object/particle merge order, visual center, and the untextured slot. Installed September 2013 exposure remains zero. Final F2 source audit found no additional defect. Return gates: target 1/1; unchanged focused baseline 95/95; AP pin 1/1; real allocation 2/2 at 0 B; shader/manifest 32/32; Release 0W/0E; one discriminating mutation recorded in packet §20.4. | G3/G4 UNPASSED | Final retail review of the no-Surface branch and wording, then sequential production/gate-honesty review of the complete c3a stack. Any further code, test, register, or evidence finding is a third fix round and stops c3a; c3b remains locked. |
 | S5 | — | G4 | fill |
 
 ---

docs/research/2026-09-01-overhaul/s4-depth-alpha-packet.md

@@ -1702,3 +1702,69 @@ no-surface branch and evidence wording first. Only PASS unlocks the sequential
 production/gate-honesty lens over the complete c3a stack. Any further code,
 test, register, or evidence correction would be a third fix round: stop the
 chunk and write it up; do not land or graphically gate it.
+
+### 20.4 Final-fix implementation result (Sonnet, 2026-09-04)
+
+**IMPLEMENTED — FINAL RETAIL REVIEW REQUIRED.** A successfully decoded GfxObj
+now retains its complete `ParticleGfxInfo` when `SurfaceId == 0`; texture
+acquisition alone remains conditional on a nonzero Surface DID. Missing or
+unreadable GfxObjs and descriptors without a GfxObj retain the existing
+`Default` behavior. The production-path synthetic GfxObj test supplies no
+Surface DID or entry, a nonzero authored center distinct from its vertex-AABB
+center, size 2, and a nonidentity orientation. It proves authored distance²
+40, ordinary-object-then-particle merge order against distance² 49, the
+unchanged visual center `(10,4,0)`, and an unassigned texture slot. The
+evidence comment now calls both fixtures “production-path GfxObj-backed
+synthetic DAT records,” not real or installed DATs.
+
+Required §20.2 final-round source audit found no additional defect:
+
+- `PrepareForCellAlpha` clears and rebuilds only reconstruction records; it
+  does not add source payload to `_deferredAlpha`.
+- `PreparedParticleAlphaSubmission.Append` calls
+  `ReservePreparedDispatchDeferredParticle` exactly once at the visibility
+  edge, then calls `TryAppend` once.
+- A false return rolls back that exact tail once outside the `try`; an
+  exception rolls it back once in the `catch` and rethrows. The rollback
+  method rejects any non-tail token, so an accepted earlier token cannot be
+  renumbered or removed.
+- `RetailAlphaQueue.TryAppend` registers the source before its capacity
+  return. A rejected first-use source therefore still participates in the
+  next flush/end/abort reset while owning no rejected payload. Accepted token
+  indices remain stable.
+- Independent retained counters admit only the first 3,000 CLIP and first
+  3,000 ALPHA candidates from the already stable particle order. The row-2
+  immediate action is computed independently of retention, so candidate
+  3,001 still draws immediately.
+- Flush, EndFrame, and AbortFrame reset `_deferredAlpha`, prepared RHI count,
+  and `_preparedCellAlphaScratch`; the next preparation also clears the
+  scratch before any early return or rebuild. The immediate-exception path
+  holds no source payload and converges on that next preparation/abort.
+- The prepared list can retain at most 6,000 records and therefore at most the
+  8,192-slot `List<T>` geometric backing pinned by the diagnostic. Its bytes
+  remain included in `RetainedAlphaScratchBytes`.
+- The real warmed driver/particle/dispatcher merge and the immediate-particle
+  RHI path both still measure zero managed bytes.
+
+Mutation ledger: restoring candidate `eea5793d2`'s
+`SurfaceId == 0 ? ParticleGfxInfo.Default : ...` ternary made
+`CellTurn_GfxObjBillboardWithoutSurfaceRetainsAuthoredSortCenterAndUntexturedFallback`
+first fail its authored-distance assertion: expected `40`, actual `100`.
+The mutation was restored before the return matrix.
+
+Automated return:
+
+- targeted no-surface production path — PASS, 1/1 after mutation restore;
+- unchanged §19 focused baseline (excluding the separately executed new
+  target) — PASS, 95/95, 0 skipped;
+- AP-241/AP-242/AP-243 boundary/count pin — PASS, 1/1;
+- real production allocation pins — PASS, 2/2, both asserting 0 B;
+- shader/manifest/SPIR-V lane — PASS, 32/32;
+- Release solution build — PASS, 0 warnings / 0 errors;
+- `git diff --check` — PASS (only the repository's LF-to-CRLF working-copy
+  notices).
+
+Only `ParticleRenderer.cs`, `WalkFrameDriverTests.cs`, this packet, and the
+S4-c3a plan-ledger row changed. AP rows, queue/router/pipeline/shader/manifest/
+package behavior, and installed content remain unchanged. No graphical client
+was launched.

src/AcDream.App/Rendering/ParticleRenderer.cs

@@ -1114,14 +1114,16 @@ public sealed unsafe partial class ParticleRenderer : IDisposable
             _particleGfxInfoByGfxObj[gfxObjId] = info;
         }
 
-        resolved = info.SurfaceId == 0
-            ? ParticleGfxInfo.Default
-            : info with
+        resolved = info;
+        if (info.SurfaceId != 0)
+        {
+            resolved = info with
             {
                 TextureSlot = _textures.AcquireParticleTexture(
                     emitter.Handle,
                     info.SurfaceId),
             };
+        }
         _particleGfxInfoByEmitter.Add(emitter.Handle, resolved);
         return resolved;
     }

tests/AcDream.App.Tests/Rendering/Walk/WalkFrameDriverTests.cs

@@ -1972,10 +1972,10 @@ public sealed partial class WalkFrameDriverTests
     }
 
     /// <summary>
-    /// S4-c3a fix round 1 F1: the real DAT-backed mode-2 path keeps the GfxObj
-    /// SortCenter distinct from its vertex-AABB visual center. The particle is
-    /// at (10,0,0), sized 2 and rotated +90 degrees around Z: authored
-    /// SortCenter (1,2,0) therefore lands at (6,2,0), distance² 40. The AABB
+    /// S4-c3a fix round 1 F1: production-path GfxObj-backed synthetic DAT
+    /// records keep SortCenter distinct from the vertex-AABB visual center.
+    /// The particle is at (10,0,0), sized 2 and rotated +90 degrees around Z:
+    /// authored SortCenter (1,2,0) lands at (6,2,0), distance² 40. The AABB
     /// center (2,0,0) remains the viewer-facing draw center at (10,4,0).
     /// The ordinary object at distance² 49 must win the cross-source merge.
     /// </summary>
@@ -2109,6 +2109,132 @@ public sealed partial class WalkFrameDriverTests
         fx.AlphaQueue.AbortFrame();
     }
 
+    /// <summary>
+    /// S4-c3a final fix round: a successfully decoded GfxObj without a Surface
+    /// still owns its authored SortCenter, bounds-derived visual center, axes,
+    /// and degrade mode. Only texture acquisition is absent. With the same
+    /// scale/orientation geometry as the surfaced sibling above, CYpt remains
+    /// distance² 40, the ordinary object at distance² 49 stays first, and the
+    /// billboard retains its untextured slot plus visual center.
+    /// </summary>
+    [Fact]
+    public void CellTurn_GfxObjBillboardWithoutSurfaceRetainsAuthoredSortCenterAndUntexturedFallback()
+    {
+        using var fx = new DispatcherFixture();
+        const uint cellId = 0x8C0400A2u;
+        const uint objectGfx = 0x02000CA2u;
+        const uint particleGfx = 0x01000CA2u;
+        const uint degradeId = 0x11000CA2u;
+        InjectRenderData(fx.Manager, objectGfx, MakeFlatMesh(
+            MakeBatch(0x08100CA2u, TranslucencyKind.AlphaBlend, 0, 0, 3, 1)));
+        var worldData = new FakeWorldData();
+        worldData.OutdoorStaticsByCell[cellId] = new WalkFrameStaticRecords(
+            new[] { MakeRecord(1, 0, new Vector3(7, 0, 0),
+                [new MeshRef(objectGfx, Matrix4x4.Identity)]) },
+            0x8C04u);
+
+        var gfx = new GfxObj
+        {
+            Id = particleGfx,
+            Flags = GfxObjFlags.HasDIDDegrade,
+            DIDDegrade = degradeId,
+            SortCenter = new Vector3(1, 2, 0),
+            VertexArray = new VertexArray
+            {
+                Vertices =
+                {
+                    [0] = new SWVertex { Origin = new Vector3(1, 0, -1) },
+                    [1] = new SWVertex { Origin = new Vector3(3, 0, 1) },
+                },
+            },
+        };
+        var degrade = new GfxObjDegradeInfo
+        {
+            Id = degradeId,
+            Degrades =
+            {
+                new GfxObjInfo
+                {
+                    Id = particleGfx,
+                    DegradeMode = 2u,
+                    MaxDist = float.MaxValue,
+                },
+            },
+        };
+        using var dats = new NoopDatReaderWriter();
+        dats.Add(particleGfx, gfx);
+        dats.Add(degradeId, degrade);
+        using var textures = new TextureCache(fx.Device, dats);
+
+        var particles = new ParticleSystem(new EmitterDescRegistry(), new Random(42));
+        Quaternion orientation = Quaternion.CreateFromAxisAngle(Vector3.UnitZ, MathF.PI / 2f);
+        int handle = particles.SpawnEmitter(
+            new EmitterDesc
+            {
+                DatId = 0x32000CA2u,
+                Type = AcDream.Core.Vfx.ParticleType.Still,
+                GfxObjId = particleGfx,
+                MaxParticles = 1,
+                InitialParticles = 1,
+                LifetimeMin = 100f,
+                LifetimeMax = 100f,
+                StartAlpha = 1f,
+                EndAlpha = 1f,
+                StartSize = 2f,
+                EndSize = 2f,
+                Gravity = Vector3.Zero,
+            },
+            new Vector3(10, 0, 0),
+            orientation);
+        particles.UpdateEmitterOwnerCell(handle, cellId);
+        using var renderer = new ParticleRenderer(
+            fx.Device,
+            fx.FrameLifetime,
+            fx.Scope,
+            particles,
+            textures,
+            dats,
+            fx.MeshAdapter,
+            fx.AlphaQueue);
+        var leaf = new ProductionParticleLeaf(
+            particles, renderer, new IdentityCamera(), Vector3.Zero);
+        var driver = new WalkFrameDriver(fx.Dispatcher, leaf, worldData);
+        var ctx = new TestContext();
+        IWalkEventSink sink = driver;
+
+        using DrawScope draw = fx.BeginDraw(beginAlpha: true);
+        renderer.BeginFrame(frameSlot: 0);
+        driver.BeginFrame(ctx, Matrix4x4.Identity, Vector3.Zero);
+        var activeViews = new WalkPortalView();
+        WalkCopyView.AppendFullViewportQuad(
+            activeViews, ctx.Rays, ctx.WorldViewpoint, ctx.ViewportWidth, ctx.ViewportHeight);
+        sink.OnLandscapeViews(activeViews);
+        sink.OnLandscapeCellTurn(cellId);
+        driver.EndFrame();
+        driver.Replay(draw.Frame, draw.Pass);
+
+        IList payload = DeferredParticlePayload(renderer);
+        object deferred = Assert.Single(payload.Cast<object>());
+        object billboard = deferred.GetType().GetProperty("Billboard")!.GetValue(deferred)!;
+        object instance = billboard.GetType().GetProperty("Instance")!.GetValue(billboard)!;
+        float authoredDistanceSq = (float)instance.GetType().GetField("DistanceSq")!.GetValue(instance)!;
+        Assert.Equal(40f, authoredDistanceSq, precision: 4);
+        Assert.Equal(
+            [typeof(WbDrawDispatcher), typeof(ParticleRenderer)],
+            QueueAlphaEntries(fx.AlphaQueue)
+                .Select(static entry => entry.Source.GetType().DeclaringType));
+
+        Vector3 visualCenter = (Vector3)instance.GetType().GetField("Position")!.GetValue(instance)!;
+        GpuTextureSlot textureSlot = (GpuTextureSlot)instance.GetType().GetField("TextureSlot")!
+            .GetValue(instance)!;
+        Assert.True(
+            Vector3.Distance(new Vector3(10, 4, 0), visualCenter) < 1e-4f,
+            $"Visual center was {visualCenter}, expected <10, 4, 0>.");
+        Assert.False(textureSlot.IsAssigned);
+
+        fx.AlphaQueue.AbortFrame();
+    }
+
     [Fact]
     public void SeparateCellTurnsRemainCellMajorWhenLaterCellIsFarther()
     {