An enumeration of directions the handle moves in.
| PositiveX | This value corresponds to the handle moving in a positive direction away from PrimitiveBoundsHandle.center along the x-axis. |
| NegativeX | This value corresponds to the handle moving in a negative direction away from PrimitiveBoundsHandle.center along the x-axis. |
| PositiveY | This value corresponds to the handle moving in a positive direction away from PrimitiveBoundsHandle.center along the y-axis. |
| NegativeY | This value corresponds to the handle moving in a negative direction away from PrimitiveBoundsHandle.center along the y-axis. |
| PositiveZ | This value corresponds to the handle moving in a positive direction away from PrimitiveBoundsHandle.center along the z-axis. |
| NegativeZ | This value corresponds to the handle moving in a negative direction away from PrimitiveBoundsHandle.center along the z-axis. |