(ui-motion {inertia|constrain|own-coordinates} {on|off})Enable or disable certain properties of mouse-controlled motion. The purpose of this command is to give access to the respective toggles of the Main panel’s Motion menu through GCL commands. See Using the Mouse to Manipulate Objects.
inertiaNormally, moving objects have inertia: if the mouse is still moving when
the button is released, the selected object continues to move. When
inertia is off, objects cease to move as soon as you release the
mouse.
constrainIt’s sometimes handy to move an object in a direction aligned with a
coordinate axis: exactly horizontally or vertically. Calling
(ui-motion constrain on) changes the interpretation of mouse
motions to allow this; approximately-horizontal or
approximately-vertical mouse dragging becomes exactly horizontal or
vertical motion. Note that the motion is still along the X or Y axes of
the camera in which you move the mouse, not necessarily the object’s own
coordinate system.
own-coordinatesIt’s sometimes handy to move objects with respect to the coordinate
system where they were defined, rather than with respect to some
camera’s view. When (ui-motion own-coordinates on) has been
called, all motions are interpreted that way: dragging the mouse
rightward in translate mode moves the object in its own +X
direction, and so on. May be especially useful in conjunction with the
(ui-motion constrain on) command.