Reply To: 3d droplet impact
For the cylinder2d example the most relevant line is 91:
superGeometry.rename( 1,5, circle );
This changes the fluid cells overlapped by the given circle indicator to 5. In prepareLattice cells of material 5 are then handled by either plain or interpolated bounce back. If you want to exchange the circle with another obstacle geometry, you only need to change the circle indicator to some other indicator class (e.g. IndicatorCuboid2D for a rectangular shape).