---
name: feedback-isolate-rebar-layers-gotcha
description: When isolating rebar in the P1 model, the C12~C18 stirrup content lives on layer P1_두부(코핑) — never turn that layer off; hide the concrete objects individually
metadata:
  type: feedback
---

All leaf objects inside the C12~C18 block definitions (152/137/130/338/130/137/152 leaves) are on layer `P1_두부(코핑)` (ColorFromParent, so they draw in the mark layer's colour). Turning that layer off makes the stirrups vanish even though layers C12_H22…C18_H22 are on (user: "철근이 켜져있는데 안보여 … 다 어디로 날려보냈니?"). C1~C11 and C19~C25 leaves sit on their own mark layers and are fine.

**Why:** happened 2026-10-06 when the user asked "C22,C24 철근이랑 주철근만 켜줘" and I hid every other layer; cost several turns of debugging (I first blamed camera positions/zoom).
**How to apply:** to show rebar only, keep `P1_두부(코핑)` ON and hide its 3 objects (coping solid + 2 construction lines) with rs.HideObject; the user restores with Show. Also remember `doc.Objects` iteration skips objects on off layers unless ObjectEnumeratorSettings.HiddenObjects=True. Previous visibility state of all layers: `261006_layer_visibility_before_isolate.json` in the drawings folder. See [[project-p1-final-model-state-261006]].