diff --git a/assets/3DModelle/README.md b/assets/3DModelle/README.md
index 4651460..7a05f58 100644
--- a/assets/3DModelle/README.md
+++ b/assets/3DModelle/README.md
@@ -24,6 +24,18 @@ Einmal sofort: `python3 scripts/tools/organize_3d_models.py --force --import`
 **Random-Dorf:** Häuser außer `massour/`; Tiere außer `cow/` (Kuh = Masseur **im Dorf**).  
 **Größen:** Spieler = **1,74 m** (`SpriteFit.WORLD_PLAYER_HEIGHT`); Häuser ~8,5 m, Kuh ~1,5 m, Tiere artgerecht (Katze ~28 cm … Giraffe ~3,4 m). Scale-Lab / `data/model_scales.json` überschreibt Fits.
 
+## Scale Lab (Editor)
+
+Open **`scenes/dev/scale_lab.tscn`** in Godot (File → Open, or drag into viewport). Not in the main game flow.
+
+1. Pick a model in the list (all GLBs under `animals/`, `houses/`, `props/`).
+2. Compare against the **measuring wall** (0.1 m ticks, labels every meter, red mark at **1.74 m**) and the blue **player capsule**.
+3. Adjust `fit_height` / `fit_max_width` → live preview via `ModelProp`.
+4. **Save** writes **`data/model_scales.json`**. Village, massage studio, and every `ModelProp` with `use_scale_catalog` read that file at runtime.
+5. **Reset defaults** restores built-in SpriteFit tables (save again to persist).
+
+Keys are `category/folder` (e.g. `animals/chimp`). Missing keys fall back to `SpriteFit` constants.
+
 ## Editor-Vorschau (WYSIWYG)
 
 Ohne Play sehen, wo Billboards und 3D-Props landen: