An introduction to this tool is covered in the video in Example 3: Small Landowner Inventory
Use SHIFT+Left Click to select an object on the terrain.
Move allows you to move the object by clicking and dragging the Transform Handles. Click the arrows to move along the X, Y, and Z axis or click on the squares to move the object in two directions at once.
Rotate allows you to spin the object. Each color represents a separate rotation axis.
Scale allows you to increase or decrease the size of the object. Scale the object uniformly by clicking and dragging the white cube, or adjust the scale along each axis separately. Note: scaling a tree will not affect the data that is attached to it.