V.2.21 Verified — Ff2d

Before refinement: 128 elements, max error 12% After 2 passes: 1,204 elements, max error 3.1%

Select the Inject Brush tool ( I ). Choose Density Source = 1.0, Temperature = 2.5 (buoyant force). Paint a small horizontal line at the bottom center of the screen. ff2d v.2.21