src/hooks/useLine.js

@@ -38,12 +38,12 @@ export const useLine = () => {
     line.set({
       visible: false,
     })
-    canvas
-      ?.getObjects()
-      .find((obj) => obj.parentId === line.id)
-      .set({
+    const obj = canvas?.getObjects().find((obj) => obj.parentId === line.id)
+    if (obj) {
+      obj.set({
         visible: false,
       })
+    }
     canvas?.renderAll()
   }
 

src/hooks/usePolygon.js

@@ -1110,7 +1110,7 @@ export const usePolygon = () => {
           defense = 'north'
           break
       }
-      pitch = polygon.lines[index].attributes?.pitch ?? 0
+      pitch = polygon.lines[index]?.attributes?.pitch ?? 0
 
       const roof = new QPolygon(roofPoint, {
         fontSize: polygon.fontSize,