1️⃣ Model: Add Cylinder → delete top face → extrude neck. Duplicate, scale inside = liquid. 2️⃣ Cut line: Add Cube (flat “slice”). On liquid: Boolean - Difference (Object: Cube). Parent liquid to bottle (Ctrl P). 3️⃣ Keep level: Add Empty, parent to bottle. On Cube: Constraint - Copy Location (Target: Empty, Z only, Offset on). Rotate bottle — the Cube’s Z stays level. 4️⃣ Ripples: Subdivide Cube. Physics on Cube: Dynamic Paint - Canvas (Waves). On bottle: Dynamic Paint - Brush. Press Play and r