title: Basic Tag and Glue
author: tiglari

<img border=1 align=right> contextmenu.png </img>
The most basic operation is to first tag a face, with the right
mouse menu for faces, and then select another face, and click
on the 'glue to tagged' command on the right mouse menu.  The
selected face will then snap to the position of the tagged one.
This command is useful for getting things into alignment, especially
off the grid.

Below the 'Glue to Tagged' item is a submenu 'More Tagging',
which offers additional commands:

<ul>
<LI>Add to tagged - the selected face will join the currently
tagged face(s) to form or enlarge a set of tagged faces, which
is useful for various things.

<LI>Removed from tagged - the selected face is removed from the
tagged set.

<LI>Clear tag - all tags are erased

<LI>Select tagged list - the tagged list becomes the multi-selection.
This can be useful if you want to make a multi-selection of faces
from different brushes, since you otherwise you need the tree-view
to do this (if you have a face selected, to select one from another
brush you have to select that brush, which looses your face selection).
</ul>

So far we've only looked at the face menu.  Tag Side also puts commands
on the speedmenus for other things, such as vertices.

Vertices have Tag Point and Glue to Tagged, and vertices can be
glued to each other and to faces, and vice-versa.  For example,
if you have a downward-sloping brush that is functioning as
a ramp, and you want to align level surfaces precisely with
the top and bottom of the ramp, you can tag the upper vertices,
and glue the top of a brush to them.
Empty points in
space can also be tagged (the background menu), tho I'm not sure at
this point how useful this really is.

A more complicated command on the vertex menu is 'align face to tagged'.
If you tag a face, then select a side (left mouseclick its handle),
then the 'align selection to tagged' command will appear on the
speedmenu of the face's vertices.  This will swivel the face around
the vertex so that it is parallel to the tagged face.  This can
be used to align the ceiling of a sloping tunnel exactly
parallel to the floor.

Finally there are some commands on the speedmenu for polys:

<ul>
<LI>Glue Linked Faces - covered <a href="#later">later</a>,
when we talk about <ref> ./linking </ref>.

<LI>Merge Polys - you can merge brushes that 'kiss' at a face
(the polys each have a brush with the same location, orientiation,
size and shape, but pointing in opposite directions), as long as
this won't change the overall shape or create an invalid poly.
To use it, tag the kissing face in one of the brushes, and select
the other brush, and if everything is cool the menu item should
become enabled.

<LI>Cut poly along along tagged - So you can use some face of
a brush as a cutting plane for other polys.
</UL>
