New in 3.1: • Bring your own 3D model: import an STL from Build, Files, Mail or AirDrop. Pick its unit and a model scale (the largest that fits is suggested), and full-scale numbers follow your scale. • New template, Mystery dam: a dam and spillway built from an STL at 1:100. The dry valley fills, spills, and the jump forms in the stilling basin. • Models and shapes can poke through the walls and floor; only the part inside the tank counts. • Snap guides, duplicate in place, and resizable 2D shapes. • Sides: "Allow inflow" on water levels, and "Start empty" for a dry start. • Iso, Front, Top and Side views in Build, clearer In and Out numbers, and many small fixes.