Aligning objects by the center, bottom, or top of their bounding boxes
You can align any two objects, with one as the source object that takes on the alignment of the target object. There are many uses for this feature. For precision, an important use is grid alignment. You can create a new grid object and align it to an existing object, either manually or automatically with the AutoGrid feature. Conversely, you can move an object onto a grid anywhere in your scene.
Alignment involves two objects: one is the source object, where the process begins; the other is the target object, where the selection process ends.
Source object: Object you want to move into alignment with another object. You select a source object to begin the alignment process.
Target object: Object used to define the alignment. You select the target object during the alignment process. It cannot be selected beforehand.
After selecting the source object, choose Tools menu > Align or click the Align button on the main toolbar, then select the target object. Next, the Align Dialog appears.
The effects of alignment depend on the current reference coordinate system, such as View, World, and Local. You should decide what system you want to use before beginning alignment.
Reference Coordinate System: Determines the axes used for positional alignment and the size of the bounding box for maximum and minimum positions.
To align objects using active grid axes:
Choose Grid as the reference system from the list on the main toolbar.
To align two objects using their own axes:
Choose Local as the reference system. Alignment is then strictly between the two objects. Object bounding boxes determine maximum and minimum positions.
As a reminder, the current reference system appears in parenthesis following the Align Position label in the Align Selection dialog.
Alignment controls are on a single dialog. As you make a setting, the object being aligned moves immediately to the new position. This lets you experiment with alignment until you get what you want. Settings can be made in any order.
You can also work step-by-step, by applying position choices, for example, before deciding on final orientation. You can cancel at any time, returning the scene to its original state. You can also undo any alignment and start over.
Aligning multiple objects to the arrow object (each photo is adjusted in a different correction)
When you select multiple objects for alignment, the same settings apply to all of them. However, the effect on each source object is different. In practice, you're aligning separate objects at the same time with the same settings.
To align a collection of objects as a single unit, select the objects and group them. The alignment now takes place relative to the pivot and bounding box of the entire group.
You can use Align with any selection that can be transformed. The tripod axis becomes the source for alignment. You do this by accessing the sub-object level of the object before clicking Align.
For further discussion of the Align options, see Align Dialog.