> Align faces tips

Align faces tips
Problem #1:
Align might create a wrong or no solution because of the incorrect "opposite" setting. For closed faces like cylinders and tori this may make a difference in selecting from multiple possible solutions.
Possible Solution:
If the face normals of the change face and the reference face of the expected result is flipped by approximately 180 degrees you need to activate the opposite option.
Problem #2:
The geometry of the reference face is not large enough to come into contact with all neighboring faces of the changed face.
Possible Solutions:
Add the faces that do not touch the reference face to the changed faces (here the small side faces of the block).
For freeform geometry use the Untrim command to enlarge the reference geometry until it intersects with all neighbor faces.
If there is no connection (intersection) with all neighboring faces of the changed faces, the align operation fails.
Problem #3:
The change face may have a tangential neighbor that does not intersect with the reference face.
Possible Solution:
If you want to replace more than one face of a tangential face set you need to specify all faces of the face set at once (multi-face align)