Planets are orbiting around gravity fields and are also slightly attracted by each other.
The generated space warp is visualized by the deformed grid.
The gravity fields can be moved and scaled.
'r' - reset scene
't' - show/hide text-labels
'm' (pressed) + mouse:
>> 'm' (pressed) + place the mouse near the gravityField you want to edit ( sphere gets orange)
>> 'm' (pressed) + left-mouse-button: move gravityFields.
>> 'm' (pressed) + right-mouse-button (move mouse up or down): scale the gravity