From aa6c1f72a6659d3b70dc4e361ec653c88485fd4f Mon Sep 17 00:00:00 2001
From: Your Name <your.email@example.com>
Date: Tue, 9 Jun 2026 15:14:38 +0800
Subject: [PATCH] fix: replace existing world3d node before importing

---
 app/canvas/[id]/model3d/page.tsx | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/app/canvas/[id]/model3d/page.tsx b/app/canvas/[id]/model3d/page.tsx
index 87d2fcaec..85c0a73aa 100644
--- a/app/canvas/[id]/model3d/page.tsx
+++ b/app/canvas/[id]/model3d/page.tsx
@@ -650,6 +650,8 @@ export default function CanvasModel3DPage() {
 
   const viewport = useCanvasStore(canvasSelectors.viewport);
   const addNode = useCanvasStore((state) => state.addNode);
+  const nodes = useCanvasStore(canvasSelectors.nodes);
+  const deleteNode = useCanvasStore((state) => state.deleteNode);
   const getCanvasState = useCanvasStore((state) => state.getCanvasState);
 
   const [workspaceMode, setWorkspaceMode] = useState<WorkspaceMode>("model");
@@ -2032,6 +2034,15 @@ export default function CanvasModel3DPage() {
     const y =
       (stageHeight * 0.45 - viewportY) / viewportZoom - targetHeight / 2;
 
+    if (isWorldTask) {
+      const worldNodeIds = nodes
+        .filter((node) => node.type === "world3d")
+        .map((node) => node.id);
+      for (const nodeId of worldNodeIds) {
+        deleteNode(nodeId);
+      }
+    }
+
     addNode(
       isWorldTask
         ? {