1, press the use of the shortcut key SHIFT + V:
"1" first select the Model a you want to align, "align object A to object B".
"2" presses the shortcut key Shift + V, at which point the mouse is moved to each vertex of model A, and a small box appears on each vertex.
"3" left click on one of the small boxes, drag the mouse to a vertex of another object B, you will find that the vertex of model A is aligned to the vertex of model B, thus realizing the function of Model a alignment to model B.
After the "4" alignment is complete, you will find that the point on Model A still shows a small box, and then press the shortcut key Shift + V to turn off the alignment function.
2, press the use of the shortcut key V:
"1" first select the Model a you want to align, "align object A to object B".
"2" Press and hold V, at which point the mouse is moved to each vertex of model A, and a small box appears on each vertex.
"3" left click on one of the small boxes, drag the mouse to a vertex of another object B, you will find that the vertex of model A is aligned to the vertex of model B, thus realizing the function of Model a alignment to model B.
When the "4" alignment is complete, release the keyboard V key to turn off the alignment function.
u3d Alignment function