First define the base of the object by dragging with LMB. Next, release LMB and move the mouse to define the height of the object. Finally, click LMB to confirm the shape of the object.
You can use the following hotkeys to temporarily change a setting (for as long as the key is held):
Toggles the Origin setting.
Toggles the Aspect setting.
The initial depth (from the screen into the scene) used when placing the object.
Start placing on the surface under the mouse cursor. If there is no surface, this does the same as Cursor Plane.
Start placing on a plane that goes through the 3D Cursor and is aligned according to the Orientation and Plane Axis.
Start placing on a plane that goes through the 3D Cursor and is aligned to the view.
The new object's orientation -- a set of three axes, out of which Plane Axis chooses one.
The object uses the normal orientation of the surface under the mouse cursor. If there is no surface, this does the same as Default.
The object uses the default 变换方向.
Snap to the target defined in the global snapping options.
Which of the three Orientation axes (X, Y or Z) is "up" for the object. The object's base will be perpendicular to this axis.
Rather than using the Orientation axis indicated by Plane Axis, use the one that's closest to the viewport's viewing direction (when not hovering over a surface).
How the base is defined.
The base is defined from one corner to the opposing corner.
The base is defined from the centerpoint to a corner.
Whether the base has a free or fixed aspect ratio.
The width and depth of the base can be chosen independently.
The width and depth of the base are forced to be equal.
How the height is defined.
The base becomes the bottom, after which you define the top.
The base becomes the center, after which you define the top.
Whether the object's side has a free or fixed aspect ratio.
The height can be chosen independently of the base.
The height is forced to be equal to the largest side of the base.