fix: improve ceiling handle feedback and WebGPU placeholders

packages/viewer/src/systems/ceiling/ceiling-system.tsx

@@ -131,6 +131,8 @@ export function generateCeilingGeometry(
     // the whole command encoder.
     const degenerate = new THREE.BufferGeometry()
     degenerate.setAttribute('position', new THREE.Float32BufferAttribute(new Float32Array(9), 3))
+    degenerate.setAttribute('normal', new THREE.Float32BufferAttribute(new Float32Array(9), 3))
+    degenerate.setAttribute('uv', new THREE.Float32BufferAttribute(new Float32Array(6), 2))
     return degenerate
   }
 

packages/viewer/src/systems/roof/roof-system.tsx

@@ -152,6 +152,14 @@ export const RoofSystem = () => {
                 'position',
                 new THREE.Float32BufferAttribute(new Float32Array(9), 3),
               )
+              placeholder.setAttribute(
+                'normal',
+                new THREE.Float32BufferAttribute(new Float32Array(9), 3),
+              )
+              placeholder.setAttribute(
+                'uv',
+                new THREE.Float32BufferAttribute(new Float32Array(6), 2),
+              )
               computeGeometryBoundsTree(placeholder)
               mesh.geometry = placeholder
             }

packages/viewer/src/systems/stair/stair-system.tsx

@@ -531,6 +531,8 @@ function createEmptyGeometry(): THREE.BufferGeometry {
   // unbound and the draw is rejected ("Vertex buffer slot 0 … was not set"),
   // poisoning the command encoder. The count-0 groups keep nothing drawn.
   geometry.setAttribute('position', new THREE.Float32BufferAttribute(new Float32Array(9), 3))
+  geometry.setAttribute('normal', new THREE.Float32BufferAttribute(new Float32Array(9), 3))
+  geometry.setAttribute('uv', new THREE.Float32BufferAttribute(new Float32Array(6), 2))
   geometry.addGroup(0, 0, STAIR_TREAD_MATERIAL_INDEX)
   geometry.addGroup(0, 0, STAIR_SIDE_MATERIAL_INDEX)
   return geometry