What am I looking at?
Drag a shape to move it; drag empty air to orbit. Ctrl-drag turns pitch (vertical) and yaw (horizontal); Ctrl+Shift-drag horizontally changes roll. Alt works instead of Ctrl, including on Mac. Start on an object to select it, or on empty air to rotate the selected object. Shift-drag alone orbits. Use the position sliders to move precisely in all three dimensions. Editing a free object holds it again.
Each object’s force and torque come from momentum exchanged with the simulated air. Drag is along the tunnel (X), lift is upward (Y), and side force is depth (Z). Arrows show the resultant force, with length capped for readability. Readings are smoothed in time.
Forces are in lattice simulation units, not newtons. Released bodies use these measured forces with bounded motion, relative mass, damping, and approximate contact envelopes. Moving boundaries and the coarse grid limit accuracy.
Flow trails trace the current three-dimensional velocity field. Their moving highlights show direction, not individual smoke particles. A slice cuts through the velocity or pressure field.
Moving objects preserves the wake. Adding or removing objects also keeps the surrounding flow; newly uncovered cells are refilled. Reset flow starts the air over without rearranging the objects.