Fix floor item placement cursor height

packages/editor/src/components/tools/item/placement-strategies.ts

@@ -33,7 +33,6 @@ import type {
 const DEFAULT_DIMENSIONS: [number, number, number] = [1, 1, 1]
 const LOW_PROFILE_ITEM_SURFACE_MAX_HEIGHT = 0.1
 const UPWARD_SURFACE_NORMAL_MIN_Y = 0.75
-const AUTO_SURFACE_MIN_LOCAL_Y = 0.1
 
 function isLowProfileItemSurface(item: ItemNode): boolean {
   if (item.asset.attachTo) return false
@@ -64,7 +63,7 @@ function getSurfacePlacementHeight(surfaceItem: ItemNode, event: ItemEvent, loca
     return surfaceItem.asset.surface.height * surfaceItem.scale[1]
   }
 
-  if (localPos.y < AUTO_SURFACE_MIN_LOCAL_Y) return null
+  if (!Number.isFinite(localPos.y)) return null
   return localPos.y
 }
 

packages/editor/src/components/tools/item/use-placement-coordinator.tsx

@@ -514,6 +514,10 @@ export function usePlacementCoordinator(config: PlacementCoordinatorConfig): Rea
       ceilingId: null,
       surfaceItemId: null,
     }
+    if (!asset.attachTo && placementState.current.surface === 'floor') {
+      gridPosition.current.y = 0
+      cursorGroupRef.current.position.y = 0
+    }
 
     // ---- Helpers ----
 
@@ -641,9 +645,11 @@ export function usePlacementCoordinator(config: PlacementCoordinatorConfig): Rea
 
       previousGridPos = [...result.gridPosition]
       gridPosition.current.set(...result.gridPosition)
-      // Only update X and Z for cursor - useFrame will handle Y (slab elevation)
-      cursorGroupRef.current.position.x = result.cursorPosition[0]
-      cursorGroupRef.current.position.z = result.cursorPosition[2]
+      cursorGroupRef.current.position.set(
+        result.cursorPosition[0],
+        result.cursorPosition[1],
+        result.cursorPosition[2],
+      )
 
       const draft = draftNode.current
       if (draft) draft.position = result.gridPosition