From 8d883ee2af8d7e1281e8f0bd12c8437ad149bafe Mon Sep 17 00:00:00 2001
From: connorsoohoo <connorsoohoo@gmail.com>
Date: Mon, 6 Jul 2026 00:39:57 -0700
Subject: [PATCH] viewer/nodes: fix WebGPU pipeline poisoning from missing uv2
 on slabs and empty roofs
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Slab surface/side meshes (split in buildSlabGeometry) and the empty-roof
merged-mesh fallback shipped geometry without a uv2 attribute while their
default catalog finishes (woodplank floor, roof shingles) carry an aoMap
that samples uv2. three r184's WebGPU renderer crashes mid scene pass on
the referenced-but-missing attribute, leaving the post-processing MRT
render target bound — every pipeline compiled afterwards validates
against the wrong 3-attachment framebuffer and fails ("Color target has
no corresponding fragment stage output" → Invalid RenderPipeline →
Invalid CommandBuffer on every submit), and post FX permanently falls
back after retries.

- slab/geometry.ts: emit uv2 (copy of uv) on the split top/side
  geometries, matching the ensureUv2Attribute convention.
- roof-system.tsx: the children-less merged-roof fallback used
  BoxGeometry(0,0,0), which has uv but no uv2; use
  ensureRenderableGeometryAttributes(new BufferGeometry()) instead.
- post-processing.tsx: reset the render target when a render pass throws
  so a future bad mesh costs one frame, not the whole session.

Reproduced with apps/ifc-converter loading 07-revit-architectural.ifc
(35 slabs + 2 segment-less roofs); clean console after the fix.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 packages/nodes/src/slab/geometry.ts                      | 9 ++++++++-
 .../viewer/src/components/viewer/post-processing.tsx     | 6 ++++++
 packages/viewer/src/systems/roof/roof-system.tsx         | 6 ++++--
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/packages/nodes/src/slab/geometry.ts b/packages/nodes/src/slab/geometry.ts
index 6b3c241db..b9ec1853f 100644
--- a/packages/nodes/src/slab/geometry.ts
+++ b/packages/nodes/src/slab/geometry.ts
@@ -122,7 +122,14 @@ function splitSlabFacesByFacing(geometry: BufferGeometry): {
   const build = (data: { pos: number[]; uv: number[] }) => {
     const geo = new BufferGeometry()
     geo.setAttribute('position', new Float32BufferAttribute(data.pos, 3))
-    if (data.uv.length > 0) geo.setAttribute('uv', new Float32BufferAttribute(data.uv, 2))
+    if (data.uv.length > 0) {
+      geo.setAttribute('uv', new Float32BufferAttribute(data.uv, 2))
+      // Slot finishes with an aoMap (e.g. the default woodplank) sample uv2;
+      // a referenced-but-missing attribute crashes the WebGPU renderer mid
+      // scene pass, which leaks the MRT render target and poisons every
+      // pipeline built afterwards.
+      geo.setAttribute('uv2', new Float32BufferAttribute(data.uv.slice(), 2))
+    }
     geo.computeVertexNormals()
     return geo
   }
diff --git a/packages/viewer/src/components/viewer/post-processing.tsx b/packages/viewer/src/components/viewer/post-processing.tsx
index 801b11742..44c05e3ca 100644
--- a/packages/viewer/src/components/viewer/post-processing.tsx
+++ b/packages/viewer/src/components/viewer/post-processing.tsx
@@ -598,6 +598,12 @@ const PostProcessingPasses = ({
       }
     } catch (error) {
       hasPipelineErrorRef.current = true
+      // A mid-pass exception (e.g. thrown inside a PassNode's scene render)
+      // leaves the pass's MRT render target bound on the renderer. Every
+      // pipeline compiled afterwards then validates against that 3-attachment
+      // framebuffer and fails, poisoning the rebuilt pipeline and the fallback
+      // path alike. Restore the default target before retrying.
+      ;(renderer as any).setRenderTarget?.(null)
       console.error('[viewer/post-processing] Render pass failed.', {
         retryCount: retryCountRef.current,
         rendererCtor: (renderer as any).constructor?.name,
diff --git a/packages/viewer/src/systems/roof/roof-system.tsx b/packages/viewer/src/systems/roof/roof-system.tsx
index 3a65665a2..45c44afeb 100644
--- a/packages/viewer/src/systems/roof/roof-system.tsx
+++ b/packages/viewer/src/systems/roof/roof-system.tsx
@@ -497,8 +497,10 @@ function updateMergedRoofGeometry(
 
   if (children.length === 0) {
     mergedMesh.geometry.dispose()
-    // Keep a valid position attribute so Drei's BVH can index safely.
-    mergedMesh.geometry = new THREE.BoxGeometry(0, 0, 0)
+    // Keep a valid position attribute so Drei's BVH can index safely. Must
+    // also carry uv2 — the roof finish's aoMap samples it, and a missing
+    // attribute crashes the WebGPU renderer (BoxGeometry has no uv2).
+    mergedMesh.geometry = ensureRenderableGeometryAttributes(new THREE.BufferGeometry())
     return
   }